Vulnerability-Lookup

RHSA-2026:36510

Vulnerability from csaf_redhat - Published: 2026-07-08 02:42 - Updated: 2026-07-27 01:53

Summary

Red Hat Security Advisory: Red Hat Hardened Images RPMs bug fix and enhancement update

Severity

Important

Notes

Topic: An update for Red Hat Hardened Images RPMs is now available.

Details: This update includes the following RPMs: golang1.25: * golang1.25-1.25.12-0.1.hum1 (aarch64, x86_64) * golang1.25-bin-1.25.12-0.1.hum1 (aarch64, x86_64) * golang1.25-docs-1.25.12-0.1.hum1 (noarch) * golang1.25-misc-1.25.12-0.1.hum1 (noarch) * golang1.25-src-1.25.12-0.1.hum1 (noarch) * golang1.25-tests-1.25.12-0.1.hum1 (noarch) * golang1.25-1.25.12-0.1.hum1.src (src)

Terms of Use: This content is licensed under the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/). If you distribute this content, or a modified version of it, you must provide attribution to Red Hat Inc. and provide a link to the original.

CVE-2026-39822

A flaw was found in the `os.Root` functionality of Go on Unix systems. This vulnerability allows an attacker to bypass intended directory restrictions by crafting a path that ends with a symbolic link and a trailing slash. When a file is opened in `os.Root` with such a path, the symbolic link is improperly followed, potentially leading to access to locations outside of the defined root directory. This could result in information disclosure or unauthorized file system access.

7.8 (High)


                        
                          CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CWE-59 - Improper Link Resolution Before File Access ('Link Following')

Affected products

Fixed 4 products

Product	Version	Remediation
Unresolved product id: Red Hat Hardened Images:golang1-25-main@aarch64	—	Vendor Fix fix Workaround
Unresolved product id: Red Hat Hardened Images:golang1-25-main@noarch	—	Vendor Fix fix Workaround
Unresolved product id: Red Hat Hardened Images:golang1-25-main@src	—	Vendor Fix fix Workaround
Unresolved product id: Red Hat Hardened Images:golang1-25-main@x86_64	—	Vendor Fix fix Workaround

Threats

Impact Important

CVE-2026-42505

A flaw was found in the `crypto/tls` package in Go. Handshakes utilizing Encrypted Client Hello (ECH) could lead to de-anonymization by a passive network observer. This is due to the disclosure of pre-shared key identities within the unencrypted client hello, allowing an attacker to potentially link connections.

5.3 (Medium)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

CWE-201 - Insertion of Sensitive Information Into Sent Data

Affected products

Fixed 4 products

Product	Version	Remediation
Unresolved product id: Red Hat Hardened Images:golang1-25-main@aarch64	—	Vendor Fix fix Workaround
Unresolved product id: Red Hat Hardened Images:golang1-25-main@noarch	—	Vendor Fix fix Workaround
Unresolved product id: Red Hat Hardened Images:golang1-25-main@src	—	Vendor Fix fix Workaround
Unresolved product id: Red Hat Hardened Images:golang1-25-main@x86_64	—	Vendor Fix fix Workaround

Threats

Impact Moderate

References

21 references

URL	Category
https://access.redhat.com/errata/RHSA-2026:36510	self
https://images.redhat.com/	external
https://access.redhat.com/security/cve/CVE-2026-39822	external
https://access.redhat.com/security/updates/classi…	external
https://access.redhat.com/security/cve/CVE-2026-42505	external
https://security.access.redhat.com/data/csaf/v2/a…	self
https://access.redhat.com/security/cve/CVE-2026-39822	self
https://bugzilla.redhat.com/show_bug.cgi?id=2498152	external
https://www.cve.org/CVERecord?id=CVE-2026-39822	external
https://nvd.nist.gov/vuln/detail/CVE-2026-39822	external
https://go.dev/cl/797880	external
https://go.dev/issue/79005	external
https://groups.google.com/g/golang-announce/c/Orm…	external
https://pkg.go.dev/vuln/GO-2026-4970	external
https://access.redhat.com/security/cve/CVE-2026-42505	self
https://bugzilla.redhat.com/show_bug.cgi?id=2498138	external
https://www.cve.org/CVERecord?id=CVE-2026-42505	external
https://nvd.nist.gov/vuln/detail/CVE-2026-42505	external
https://go.dev/cl/775960	external
https://go.dev/issue/79282	external
https://pkg.go.dev/vuln/GO-2026-5856	external

JSON

To clipboard

{
  "document": {
    "aggregate_severity": {
      "namespace": "https://access.redhat.com/security/updates/classification/",
      "text": "Important"
    },
    "category": "csaf_security_advisory",
    "csaf_version": "2.0",
    "distribution": {
      "text": "Copyright \u00a9 Red Hat, Inc. All rights reserved.",
      "tlp": {
        "label": "WHITE",
        "url": "https://www.first.org/tlp/"
      }
    },
    "lang": "en",
    "notes": [
      {
        "category": "summary",
        "text": "An update for Red Hat Hardened Images RPMs is now available.",
        "title": "Topic"
      },
      {
        "category": "general",
        "text": "This update includes the following RPMs:\n\ngolang1.25:\n  * golang1.25-1.25.12-0.1.hum1 (aarch64, x86_64)\n  * golang1.25-bin-1.25.12-0.1.hum1 (aarch64, x86_64)\n  * golang1.25-docs-1.25.12-0.1.hum1 (noarch)\n  * golang1.25-misc-1.25.12-0.1.hum1 (noarch)\n  * golang1.25-src-1.25.12-0.1.hum1 (noarch)\n  * golang1.25-tests-1.25.12-0.1.hum1 (noarch)\n  * golang1.25-1.25.12-0.1.hum1.src (src)",
        "title": "Details"
      },
      {
        "category": "legal_disclaimer",
        "text": "This content is licensed under the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/). If you distribute this content, or a modified version of it, you must provide attribution to Red Hat Inc. and provide a link to the original.",
        "title": "Terms of Use"
      }
    ],
    "publisher": {
      "category": "vendor",
      "contact_details": "https://access.redhat.com/security/team/contact/",
      "issuing_authority": "Red Hat Product Security is responsible for vulnerability handling across all Red Hat products and services.",
      "name": "Red Hat Product Security",
      "namespace": "https://www.redhat.com"
    },
    "references": [
      {
        "category": "self",
        "summary": "https://access.redhat.com/errata/RHSA-2026:36510",
        "url": "https://access.redhat.com/errata/RHSA-2026:36510"
      },
      {
        "category": "external",
        "summary": "https://images.redhat.com/",
        "url": "https://images.redhat.com/"
      },
      {
        "category": "external",
        "summary": "https://access.redhat.com/security/cve/CVE-2026-39822",
        "url": "https://access.redhat.com/security/cve/CVE-2026-39822"
      },
      {
        "category": "external",
        "summary": "https://access.redhat.com/security/updates/classification/",
        "url": "https://access.redhat.com/security/updates/classification/"
      },
      {
        "category": "external",
        "summary": "https://access.redhat.com/security/cve/CVE-2026-42505",
        "url": "https://access.redhat.com/security/cve/CVE-2026-42505"
      },
      {
        "category": "self",
        "summary": "Canonical URL",
        "url": "https://security.access.redhat.com/data/csaf/v2/advisories/2026/rhsa-2026_36510.json"
      }
    ],
    "title": "Red Hat Security Advisory: Red Hat Hardened Images RPMs bug fix and enhancement update",
    "tracking": {
      "current_release_date": "2026-07-27T01:53:01+00:00",
      "generator": {
        "date": "2026-07-27T01:53:01+00:00",
        "engine": {
          "name": "Red Hat SDEngine",
          "version": "5.3.7"
        }
      },
      "id": "RHSA-2026:36510",
      "initial_release_date": "2026-07-08T02:42:58+00:00",
      "revision_history": [
        {
          "date": "2026-07-08T02:42:58+00:00",
          "number": "1",
          "summary": "Initial version"
        },
        {
          "date": "2026-07-25T05:39:32+00:00",
          "number": "2",
          "summary": "Last updated version"
        },
        {
          "date": "2026-07-27T01:53:01+00:00",
          "number": "3",
          "summary": "Last generated version"
        }
      ],
      "status": "final",
      "version": "3"
    }
  },
  "product_tree": {
    "branches": [
      {
        "branches": [
          {
            "branches": [
              {
                "category": "product_name",
                "name": "Red Hat Hardened Images",
                "product": {
                  "name": "Red Hat Hardened Images",
                  "product_id": "Red Hat Hardened Images",
                  "product_identification_helper": {
                    "cpe": "cpe:/a:redhat:hummingbird:1"
                  }
                }
              }
            ],
            "category": "product_family",
            "name": "Red Hat Hardened Images"
          },
          {
            "branches": [
              {
                "category": "product_version",
                "name": "golang1-25-main@aarch64",
                "product": {
                  "name": "golang1-25-main@aarch64",
                  "product_id": "golang1-25-main@aarch64",
                  "product_identification_helper": {
                    "purl": "pkg:rpm/redhat/golang1.25@1.25.12-0.1.hum1?arch=aarch64\u0026distro=hummingbird-20251124\u0026repository_id=public-hummingbird-aarch64-rpms"
                  }
                }
              }
            ],
            "category": "architecture",
            "name": "aarch64"
          },
          {
            "branches": [
              {
                "category": "product_version",
                "name": "golang1-25-main@src",
                "product": {
                  "name": "golang1-25-main@src",
                  "product_id": "golang1-25-main@src",
                  "product_identification_helper": {
                    "purl": "pkg:rpm/redhat/golang1.25@1.25.12-0.1.hum1?arch=src\u0026distro=hummingbird-20251124\u0026repository_id=public-hummingbird-source-rpms"
                  }
                }
              }
            ],
            "category": "architecture",
            "name": "src"
          },
          {
            "branches": [
              {
                "category": "product_version",
                "name": "golang1-25-main@x86_64",
                "product": {
                  "name": "golang1-25-main@x86_64",
                  "product_id": "golang1-25-main@x86_64",
                  "product_identification_helper": {
                    "purl": "pkg:rpm/redhat/golang1.25@1.25.12-0.1.hum1?arch=x86_64\u0026distro=hummingbird-20251124\u0026repository_id=public-hummingbird-x86_64-rpms"
                  }
                }
              }
            ],
            "category": "architecture",
            "name": "x86_64"
          },
          {
            "branches": [
              {
                "category": "product_version",
                "name": "golang1-25-main@noarch",
                "product": {
                  "name": "golang1-25-main@noarch",
                  "product_id": "golang1-25-main@noarch",
                  "product_identification_helper": {
                    "purl": "pkg:rpm/redhat/golang1.25-docs@1.25.12-0.1.hum1?arch=noarch\u0026distro=hummingbird-20251124\u0026repository_id=public-hummingbird-x86_64-rpms"
                  }
                }
              }
            ],
            "category": "architecture",
            "name": "noarch"
          }
        ],
        "category": "vendor",
        "name": "Red Hat"
      }
    ],
    "relationships": [
      {
        "category": "default_component_of",
        "full_product_name": {
          "name": "golang1-25-main@aarch64 as a component of Red Hat Hardened Images",
          "product_id": "Red Hat Hardened Images:golang1-25-main@aarch64"
        },
        "product_reference": "golang1-25-main@aarch64",
        "relates_to_product_reference": "Red Hat Hardened Images"
      },
      {
        "category": "default_component_of",
        "full_product_name": {
          "name": "golang1-25-main@noarch as a component of Red Hat Hardened Images",
          "product_id": "Red Hat Hardened Images:golang1-25-main@noarch"
        },
        "product_reference": "golang1-25-main@noarch",
        "relates_to_product_reference": "Red Hat Hardened Images"
      },
      {
        "category": "default_component_of",
        "full_product_name": {
          "name": "golang1-25-main@src as a component of Red Hat Hardened Images",
          "product_id": "Red Hat Hardened Images:golang1-25-main@src"
        },
        "product_reference": "golang1-25-main@src",
        "relates_to_product_reference": "Red Hat Hardened Images"
      },
      {
        "category": "default_component_of",
        "full_product_name": {
          "name": "golang1-25-main@x86_64 as a component of Red Hat Hardened Images",
          "product_id": "Red Hat Hardened Images:golang1-25-main@x86_64"
        },
        "product_reference": "golang1-25-main@x86_64",
        "relates_to_product_reference": "Red Hat Hardened Images"
      }
    ]
  },
  "vulnerabilities": [
    {
      "cve": "CVE-2026-39822",
      "cwe": {
        "id": "CWE-59",
        "name": "Improper Link Resolution Before File Access (\u0027Link Following\u0027)"
      },
      "discovery_date": "2026-07-08T17:01:53.592869+00:00",
      "ids": [
        {
          "system_name": "Red Hat Bugzilla ID",
          "text": "2498152"
        }
      ],
      "notes": [
        {
          "category": "description",
          "text": "A flaw was found in the `os.Root` functionality of Go on Unix systems. This vulnerability allows an attacker to bypass intended directory restrictions by crafting a path that ends with a symbolic link and a trailing slash. When a file is opened in `os.Root` with such a path, the symbolic link is improperly followed, potentially leading to access to locations outside of the defined root directory. This could result in information disclosure or unauthorized file system access.",
          "title": "Vulnerability description"
        },
        {
          "category": "summary",
          "text": "os: golang: Go os.Root: Symlink following vulnerability allows directory traversal",
          "title": "Vulnerability summary"
        },
        {
          "category": "other",
          "text": "A flaw was found in Go\u0027s os.Root implementation. On Unix systems, `os.Root.Open()` improperly follows symlinks to locations outside the root directory when the path ends with a trailing slash (e.g., root.Open(\"symlink/\")). This is because `openat()` with `O_NOFOLLOW` does not prevent symlink resolution when the path has a trailing /. An attacker able to create symlinks within an os.Root directory could use this to read or write files outside the intended root. The os.Root API was introduced in Go 1.24. Go versions prior to 1.24 are not affected. This issue is fixed in Go 1.25.12 and Go 1.26.5.\n\nThe following symbols are affected:\n* `OpenInRoot`: Opens a file or directory within an `os.Root`.\n* `Root.Create`: Creates a file inside an `os.Root`.\n* `Root.Open`: Opens a path relative to an `os.Root`.\n* `Root.OpenFile`: Opens a file with specified flags and permissions inside an `os.Root`.\n* `Root.OpenRoot`: Opens a sub-root directory from an `os.Root`.\n* `Root.ReadFile`: Reads a file inside an `os.Root`.\n* `Root.WriteFile`: Writes a file inside an `os.Root`.",
          "title": "Statement"
        },
        {
          "category": "general",
          "text": "The CVSS score(s) listed for this vulnerability do not reflect the associated product\u0027s status, and are included for informational purposes to better understand the severity of this vulnerability.",
          "title": "CVSS score applicability"
        }
      ],
      "product_status": {
        "fixed": [
          "Red Hat Hardened Images:golang1-25-main@aarch64",
          "Red Hat Hardened Images:golang1-25-main@noarch",
          "Red Hat Hardened Images:golang1-25-main@src",
          "Red Hat Hardened Images:golang1-25-main@x86_64"
        ]
      },
      "references": [
        {
          "category": "self",
          "summary": "Canonical URL",
          "url": "https://access.redhat.com/security/cve/CVE-2026-39822"
        },
        {
          "category": "external",
          "summary": "RHBZ#2498152",
          "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2498152"
        },
        {
          "category": "external",
          "summary": "https://www.cve.org/CVERecord?id=CVE-2026-39822",
          "url": "https://www.cve.org/CVERecord?id=CVE-2026-39822"
        },
        {
          "category": "external",
          "summary": "https://nvd.nist.gov/vuln/detail/CVE-2026-39822",
          "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-39822"
        },
        {
          "category": "external",
          "summary": "https://go.dev/cl/797880",
          "url": "https://go.dev/cl/797880"
        },
        {
          "category": "external",
          "summary": "https://go.dev/issue/79005",
          "url": "https://go.dev/issue/79005"
        },
        {
          "category": "external",
          "summary": "https://groups.google.com/g/golang-announce/c/OrmQE_Yp5Sc",
          "url": "https://groups.google.com/g/golang-announce/c/OrmQE_Yp5Sc"
        },
        {
          "category": "external",
          "summary": "https://pkg.go.dev/vuln/GO-2026-4970",
          "url": "https://pkg.go.dev/vuln/GO-2026-4970"
        }
      ],
      "release_date": "2026-07-08T15:46:27.199000+00:00",
      "remediations": [
        {
          "category": "vendor_fix",
          "date": "2026-07-08T02:42:58+00:00",
          "details": "For details on how to apply this update, which includes the changes described in this advisory, refer to:\nhttps://images.redhat.com/",
          "product_ids": [
            "Red Hat Hardened Images:golang1-25-main@aarch64",
            "Red Hat Hardened Images:golang1-25-main@noarch",
            "Red Hat Hardened Images:golang1-25-main@src",
            "Red Hat Hardened Images:golang1-25-main@x86_64"
          ],
          "restart_required": {
            "category": "none"
          },
          "url": "https://access.redhat.com/errata/RHSA-2026:36510"
        },
        {
          "category": "workaround",
          "details": "There is no mitigation for this issue other than updating the Go toolchain to Go 1.25.12 or Go 1.26.5. Programs compiled with Go \u003e= 1.24 that do not use the os.Root API are not affected by this vulnerability.\nThe os.Root API was introduced in Go 1.24. Go versions prior to 1.24 are not affected.\nThis issue is fixed in Go 1.25.12 and Go 1.26.5.",
          "product_ids": [
            "Red Hat Hardened Images:golang1-25-main@aarch64",
            "Red Hat Hardened Images:golang1-25-main@noarch",
            "Red Hat Hardened Images:golang1-25-main@src",
            "Red Hat Hardened Images:golang1-25-main@x86_64"
          ]
        }
      ],
      "scores": [
        {
          "cvss_v3": {
            "attackComplexity": "LOW",
            "attackVector": "LOCAL",
            "availabilityImpact": "HIGH",
            "baseScore": 7.8,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "privilegesRequired": "LOW",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "products": [
            "Red Hat Hardened Images:golang1-25-main@aarch64",
            "Red Hat Hardened Images:golang1-25-main@noarch",
            "Red Hat Hardened Images:golang1-25-main@src",
            "Red Hat Hardened Images:golang1-25-main@x86_64"
          ]
        }
      ],
      "threats": [
        {
          "category": "impact",
          "details": "Important"
        }
      ],
      "title": "os: golang: Go os.Root: Symlink following vulnerability allows directory traversal"
    },
    {
      "cve": "CVE-2026-42505",
      "cwe": {
        "id": "CWE-201",
        "name": "Insertion of Sensitive Information Into Sent Data"
      },
      "discovery_date": "2026-07-08T17:01:05.490547+00:00",
      "ids": [
        {
          "system_name": "Red Hat Bugzilla ID",
          "text": "2498138"
        }
      ],
      "notes": [
        {
          "category": "description",
          "text": "A flaw was found in the `crypto/tls` package in Go. Handshakes utilizing Encrypted Client Hello (ECH) could lead to de-anonymization by a passive network observer. This is due to the disclosure of pre-shared key identities within the unencrypted client hello, allowing an attacker to potentially link connections.",
          "title": "Vulnerability description"
        },
        {
          "category": "summary",
          "text": "crypto/tls: golang: Go crypto/tls: Information disclosure in Encrypted Client Hello",
          "title": "Vulnerability summary"
        },
        {
          "category": "other",
          "text": "This Moderate-impact information disclosure flaw in the Go `crypto/tls` package allows a passive network observer to de-anonymize connections utilizing Encrypted Client Hello (ECH). The vulnerability stems from the unintentional exposure of pre-shared key identities within the unencrypted client hello, potentially enabling an attacker to link previously anonymous connections. This primarily affects the privacy of communications rather than integrity or availability.",
          "title": "Statement"
        },
        {
          "category": "general",
          "text": "The CVSS score(s) listed for this vulnerability do not reflect the associated product\u0027s status, and are included for informational purposes to better understand the severity of this vulnerability.",
          "title": "CVSS score applicability"
        }
      ],
      "product_status": {
        "fixed": [
          "Red Hat Hardened Images:golang1-25-main@aarch64",
          "Red Hat Hardened Images:golang1-25-main@noarch",
          "Red Hat Hardened Images:golang1-25-main@src",
          "Red Hat Hardened Images:golang1-25-main@x86_64"
        ]
      },
      "references": [
        {
          "category": "self",
          "summary": "Canonical URL",
          "url": "https://access.redhat.com/security/cve/CVE-2026-42505"
        },
        {
          "category": "external",
          "summary": "RHBZ#2498138",
          "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2498138"
        },
        {
          "category": "external",
          "summary": "https://www.cve.org/CVERecord?id=CVE-2026-42505",
          "url": "https://www.cve.org/CVERecord?id=CVE-2026-42505"
        },
        {
          "category": "external",
          "summary": "https://nvd.nist.gov/vuln/detail/CVE-2026-42505",
          "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-42505"
        },
        {
          "category": "external",
          "summary": "https://go.dev/cl/775960",
          "url": "https://go.dev/cl/775960"
        },
        {
          "category": "external",
          "summary": "https://go.dev/issue/79282",
          "url": "https://go.dev/issue/79282"
        },
        {
          "category": "external",
          "summary": "https://groups.google.com/g/golang-announce/c/OrmQE_Yp5Sc",
          "url": "https://groups.google.com/g/golang-announce/c/OrmQE_Yp5Sc"
        },
        {
          "category": "external",
          "summary": "https://pkg.go.dev/vuln/GO-2026-5856",
          "url": "https://pkg.go.dev/vuln/GO-2026-5856"
        }
      ],
      "release_date": "2026-07-08T15:46:33.407000+00:00",
      "remediations": [
        {
          "category": "vendor_fix",
          "date": "2026-07-08T02:42:58+00:00",
          "details": "For details on how to apply this update, which includes the changes described in this advisory, refer to:\nhttps://images.redhat.com/",
          "product_ids": [
            "Red Hat Hardened Images:golang1-25-main@aarch64",
            "Red Hat Hardened Images:golang1-25-main@noarch",
            "Red Hat Hardened Images:golang1-25-main@src",
            "Red Hat Hardened Images:golang1-25-main@x86_64"
          ],
          "restart_required": {
            "category": "none"
          },
          "url": "https://access.redhat.com/errata/RHSA-2026:36510"
        },
        {
          "category": "workaround",
          "details": "Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.",
          "product_ids": [
            "Red Hat Hardened Images:golang1-25-main@aarch64",
            "Red Hat Hardened Images:golang1-25-main@noarch",
            "Red Hat Hardened Images:golang1-25-main@src",
            "Red Hat Hardened Images:golang1-25-main@x86_64"
          ]
        }
      ],
      "scores": [
        {
          "cvss_v3": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 5.3,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "LOW",
            "integrityImpact": "NONE",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N",
            "version": "3.1"
          },
          "products": [
            "Red Hat Hardened Images:golang1-25-main@aarch64",
            "Red Hat Hardened Images:golang1-25-main@noarch",
            "Red Hat Hardened Images:golang1-25-main@src",
            "Red Hat Hardened Images:golang1-25-main@x86_64"
          ]
        }
      ],
      "threats": [
        {
          "category": "impact",
          "details": "Moderate"
        }
      ],
      "title": "crypto/tls: golang: Go crypto/tls: Information disclosure in Encrypted Client Hello"
    }
  ]
}

CVE-2026-39822 (GCVE-0-2026-39822)

Vulnerability from cvelistv5 – Published: 2026-07-08 15:46 – Updated: 2026-07-08 19:39

Title

Root escape via symlink plus trailing slash in os

Summary

On Unix systems, opening a file in an os.Root improperly follows symlinks to locations outside of the Root when the final path component of the a path is a symbolic link and the path ends in /. For example, 'root.Open("symlink/")' will open "symlink" even when "symlink" is a symbolic link pointing outside of the root.

Severity

7.8 (High)


                        
                          CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

SSVC

Exploitation: none Automatable: no Technical Impact: total

CISA Coordinator (v2.0.3)

CWE

CWE-61 - UNIX Symbolic Link (Symlink) Following

Assigner

References

4 references

URL	Tags
https://go.dev/issue/79005
https://groups.google.com/g/golang-announce/c/Orm…
https://go.dev/cl/797880
https://pkg.go.dev/vuln/GO-2026-4970

Impacted products

1 product

Vendor	Product	Version
Go standard library	os	Affected: 0 , < 1.25.12 (semver) Affected: 1.26.0-0 , < 1.26.5 (semver) Affected: 1.27.0-0 , < 1.27.0-rc.2 (semver)

Credits

Mundur (https://github.com/M0nd0R)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "cvssV3_1": {
              "attackComplexity": "LOW",
              "attackVector": "LOCAL",
              "availabilityImpact": "HIGH",
              "baseScore": 7.8,
              "baseSeverity": "HIGH",
              "confidentialityImpact": "HIGH",
              "integrityImpact": "HIGH",
              "privilegesRequired": "LOW",
              "scope": "UNCHANGED",
              "userInteraction": "NONE",
              "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
              "version": "3.1"
            }
          },
          {
            "other": {
              "content": {
                "id": "CVE-2026-39822",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-07-08T18:06:16.360721Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "problemTypes": [
          {
            "descriptions": [
              {
                "cweId": "CWE-61",
                "description": "CWE-61 UNIX Symbolic Link (Symlink) Following",
                "lang": "en",
                "type": "CWE"
              }
            ]
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-07-08T19:39:17.341Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "collectionURL": "https://pkg.go.dev",
          "defaultStatus": "unaffected",
          "packageName": "os",
          "product": "os",
          "programRoutines": [
            {
              "name": "rootOpenFileNolog"
            },
            {
              "name": "openRootInRoot"
            },
            {
              "name": "OpenInRoot"
            },
            {
              "name": "Root.Create"
            },
            {
              "name": "Root.Open"
            },
            {
              "name": "Root.OpenFile"
            },
            {
              "name": "Root.OpenRoot"
            },
            {
              "name": "Root.ReadFile"
            },
            {
              "name": "Root.WriteFile"
            },
            {
              "name": "rootFS.Open"
            },
            {
              "name": "rootFS.ReadDir"
            },
            {
              "name": "rootFS.ReadFile"
            }
          ],
          "vendor": "Go standard library",
          "versions": [
            {
              "lessThan": "1.25.12",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThan": "1.26.5",
              "status": "affected",
              "version": "1.26.0-0",
              "versionType": "semver"
            },
            {
              "lessThan": "1.27.0-rc.2",
              "status": "affected",
              "version": "1.27.0-0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "value": "Mundur (https://github.com/M0nd0R)"
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "On Unix systems, opening a file in an os.Root improperly follows symlinks to locations outside of the Root when the final path component of the a path is a symbolic link and the path ends in /. For example, \u0027root.Open(\"symlink/\")\u0027 will open \"symlink\" even when \"symlink\" is a symbolic link pointing outside of the root."
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "description": "CWE-61: UNIX Symbolic Link (Symlink) Following",
              "lang": "en"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-07-08T15:46:27.199Z",
        "orgId": "1bb62c36-49e3-4200-9d77-64a1400537cc",
        "shortName": "Go"
      },
      "references": [
        {
          "url": "https://go.dev/issue/79005"
        },
        {
          "url": "https://groups.google.com/g/golang-announce/c/OrmQE_Yp5Sc"
        },
        {
          "url": "https://go.dev/cl/797880"
        },
        {
          "url": "https://pkg.go.dev/vuln/GO-2026-4970"
        }
      ],
      "title": "Root escape via symlink plus trailing slash in os"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "1bb62c36-49e3-4200-9d77-64a1400537cc",
    "assignerShortName": "Go",
    "cveId": "CVE-2026-39822",
    "datePublished": "2026-07-08T15:46:27.199Z",
    "dateReserved": "2026-04-07T18:13:03.527Z",
    "dateUpdated": "2026-07-08T19:39:17.341Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

CVE-2026-42505 (GCVE-0-2026-42505)

Vulnerability from cvelistv5 – Published: 2026-07-08 15:46 – Updated: 2026-07-08 19:38

Title

Invoking Encrypted Client Hello privacy leak in crypto/tls

Summary

Handshakes which used Encrypted Client Hello could be de-anonymized by a passive network observer due to a disclosure of pre-shared key identities in the unencrypted client hello.

Severity

5.3 (Medium)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

SSVC

Exploitation: none Automatable: yes Technical Impact: partial

CISA Coordinator (v2.0.3)

CWE

CWE-201 - Insertion of Sensitive Information Into Sent Data

Assigner

References

4 references

URL	Tags
https://go.dev/cl/775960
https://go.dev/issue/79282
https://groups.google.com/g/golang-announce/c/Orm…
https://pkg.go.dev/vuln/GO-2026-5856

Impacted products

1 product

Vendor	Product	Version
Go standard library	crypto/tls	Affected: 0 , < 1.25.12 (semver) Affected: 1.26.0-0 , < 1.26.5 (semver) Affected: 1.27.0-0 , < 1.27.0-rc.2 (semver)

Credits

Coia Prant (github.com/rbqvq)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "cvssV3_1": {
              "attackComplexity": "LOW",
              "attackVector": "NETWORK",
              "availabilityImpact": "NONE",
              "baseScore": 5.3,
              "baseSeverity": "MEDIUM",
              "confidentialityImpact": "LOW",
              "integrityImpact": "NONE",
              "privilegesRequired": "NONE",
              "scope": "UNCHANGED",
              "userInteraction": "NONE",
              "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N",
              "version": "3.1"
            }
          },
          {
            "other": {
              "content": {
                "id": "CVE-2026-42505",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-07-08T18:03:53.821942Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "problemTypes": [
          {
            "descriptions": [
              {
                "cweId": "CWE-201",
                "description": "CWE-201 Insertion of Sensitive Information Into Sent Data",
                "lang": "en",
                "type": "CWE"
              }
            ]
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-07-08T19:38:17.603Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "collectionURL": "https://pkg.go.dev",
          "defaultStatus": "unaffected",
          "packageName": "crypto/tls",
          "product": "crypto/tls",
          "programRoutines": [
            {
              "name": "clientHelloMsg.marshalMsg"
            },
            {
              "name": "Conn.Handshake"
            },
            {
              "name": "Conn.HandshakeContext"
            },
            {
              "name": "Conn.Read"
            },
            {
              "name": "Conn.Write"
            },
            {
              "name": "Dial"
            },
            {
              "name": "DialWithDialer"
            },
            {
              "name": "Dialer.Dial"
            },
            {
              "name": "Dialer.DialContext"
            },
            {
              "name": "QUICConn.HandleData"
            },
            {
              "name": "QUICConn.SendSessionTicket"
            },
            {
              "name": "QUICConn.Start"
            }
          ],
          "vendor": "Go standard library",
          "versions": [
            {
              "lessThan": "1.25.12",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThan": "1.26.5",
              "status": "affected",
              "version": "1.26.0-0",
              "versionType": "semver"
            },
            {
              "lessThan": "1.27.0-rc.2",
              "status": "affected",
              "version": "1.27.0-0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "value": "Coia Prant (github.com/rbqvq)"
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Handshakes which used Encrypted Client Hello could be de-anonymized by a passive network observer due to a disclosure of pre-shared key identities in the unencrypted client hello."
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "description": "CWE-201: Insertion of Sensitive Information Into Sent Data",
              "lang": "en"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-07-08T15:46:33.407Z",
        "orgId": "1bb62c36-49e3-4200-9d77-64a1400537cc",
        "shortName": "Go"
      },
      "references": [
        {
          "url": "https://go.dev/cl/775960"
        },
        {
          "url": "https://go.dev/issue/79282"
        },
        {
          "url": "https://groups.google.com/g/golang-announce/c/OrmQE_Yp5Sc"
        },
        {
          "url": "https://pkg.go.dev/vuln/GO-2026-5856"
        }
      ],
      "title": "Invoking Encrypted Client Hello privacy leak in crypto/tls"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "1bb62c36-49e3-4200-9d77-64a1400537cc",
    "assignerShortName": "Go",
    "cveId": "CVE-2026-42505",
    "datePublished": "2026-07-08T15:46:33.407Z",
    "dateReserved": "2026-04-28T00:21:12.792Z",
    "dateUpdated": "2026-07-08T19:38:17.603Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.

Action not permitted

RHSA-2026:36510

CVE-2026-39822 (GCVE-0-2026-39822)

CVE-2026-42505 (GCVE-0-2026-42505)

Tags

Sightings

Nomenclature