Vulnerability-Lookup

GHSA-2JC6-HC33-HV48

Vulnerability from github – Published: 2026-05-13 18:30 – Updated: 2026-05-13 18:30

Details

Using libcurl, when a custom Host: header is first set for an HTTP request and a second request is subsequently done using the same easy handle but without the custom Host: header set, the second request would use stale information and pass on cookies meant for the first host in the second request. Leak them.

Severity

7.5 (High)


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

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JSON

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{
  "affected": [],
  "aliases": [
    "CVE-2026-6276"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-319",
      "CWE-346"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-05-13T13:01:56Z",
    "severity": "HIGH"
  },
  "details": "Using libcurl, when a custom `Host:` header is first set for an HTTP request\nand a second request is subsequently done using the same *easy handle* but\nwithout the custom `Host:` header set, the second request would use stale\ninformation and pass on cookies meant for the first host in the second\nrequest. Leak them.",
  "id": "GHSA-2jc6-hc33-hv48",
  "modified": "2026-05-13T18:30:53Z",
  "published": "2026-05-13T18:30:52Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-6276"
    },
    {
      "type": "WEB",
      "url": "https://hackerone.com/reports/3671818"
    },
    {
      "type": "WEB",
      "url": "https://curl.se/docs/CVE-2026-6276.html"
    },
    {
      "type": "WEB",
      "url": "https://curl.se/docs/CVE-2026-6276.json"
    },
    {
      "type": "WEB",
      "url": "http://www.openwall.com/lists/oss-security/2026/04/29/13"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-6276 (GCVE-0-2026-6276)

Vulnerability from cvelistv5 – Published: 2026-05-13 08:28 – Updated: 2026-09-15 06:03

Title

stale custom cookie host causes cookie leak

Summary

Using libcurl, when a custom `Host:` header is first set for an HTTP request and a second request is subsequently done using the same *easy handle* but without the custom `Host:` header set, the second request would use stale information and pass on cookies meant for the first host in the second request. Leak them.

Severity

7.5 (High)


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

SSVC

Exploitation: poc Automatable: yes Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-05-13 17:24 UTC

CWE

CWE-346 - Origin Validation Error

Assigner

curl redhat root

References

4 references

URL	Tags
https://curl.se/docs/CVE-2026-6276.json
https://curl.se/docs/CVE-2026-6276.html
https://hackerone.com/reports/3671818
http://www.openwall.com/lists/oss-security/2026/0…

Impacted products

3 products

Vendor	Product	Version
curl	curl	Affected: 7.71.0 , < 8.14.2 (semver) Affected: 8.15.0 , < 8.16.1 (semver) Affected: 8.17.0 , < 8.20.0 (semver)
curl	curl	Affected: e15e51384a423be31318b3c9c7d612a1aae661fd , < 3a19987a87f393d9394fe5acc7643f6c263c92db (git)
curl	curl	Affected: 8.19.0 Affected: 8.18.0 Affected: 8.17.0 Affected: 8.16.0 Affected: 8.15.0 Affected: 8.14.1 Affected: 8.14.0 Affected: 8.13.0 Affected: 8.12.1 Affected: 8.12.0 Affected: 8.11.1 Affected: 8.11.0 Affected: 8.10.1 Affected: 8.10.0 Affected: 8.9.1 Affected: 8.9.0 Affected: 8.8.0 Affected: 8.7.1 Affected: 8.7.0 Affected: 8.6.0 Affected: 8.5.0 Affected: 8.4.0 Affected: 8.3.0 Affected: 8.2.1 Affected: 8.2.0 Affected: 8.1.2 Affected: 8.1.1 Affected: 8.1.0 Affected: 8.0.1 Affected: 8.0.0 Affected: 7.88.1 Affected: 7.88.0 Affected: 7.87.0 Affected: 7.86.0 Affected: 7.85.0 Affected: 7.84.0 Affected: 7.83.1 Affected: 7.83.0 Affected: 7.82.0 Affected: 7.81.0 Affected: 7.80.0 Affected: 7.79.1 Affected: 7.79.0 Affected: 7.78.0 Affected: 7.77.0 Affected: 7.76.1 Affected: 7.76.0 Affected: 7.75.0 Affected: 7.74.0 Affected: 7.73.0 Affected: 7.72.0 Affected: 7.71.1 Affected: 7.71.0

Credits

Muhamad Arga Reksapati Daniel Stenberg

Show details on NVD website

JSON

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{
  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2026-05-13T09:05:37.539Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "url": "http://www.openwall.com/lists/oss-security/2026/04/29/13"
          }
        ],
        "title": "CVE Program Container"
      },
      {
        "metrics": [
          {
            "cvssV3_1": {
              "attackComplexity": "LOW",
              "attackVector": "NETWORK",
              "availabilityImpact": "HIGH",
              "baseScore": 7.5,
              "baseSeverity": "HIGH",
              "confidentialityImpact": "NONE",
              "integrityImpact": "NONE",
              "privilegesRequired": "NONE",
              "scope": "UNCHANGED",
              "userInteraction": "NONE",
              "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
              "version": "3.1"
            }
          },
          {
            "other": {
              "content": {
                "id": "CVE-2026-6276",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-05-13T17:24:29.094167Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-05-13T17:26:06.894Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "references": [
          {
            "tags": [
              "exploit"
            ],
            "url": "https://hackerone.com/reports/3671818"
          }
        ],
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "curl",
          "vendor": "curl",
          "versions": [
            {
              "lessThan": "8.14.2",
              "status": "affected",
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              "lessThan": "8.16.1",
              "status": "affected",
              "version": "8.15.0",
              "versionType": "semver"
            },
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              "status": "affected",
              "version": "8.17.0",
              "versionType": "semver"
            }
          ]
        },
        {
          "defaultStatus": "unaffected",
          "product": "curl",
          "repo": "https://github.com/curl/curl.git",
          "vendor": "curl",
          "versions": [
            {
              "lessThan": "3a19987a87f393d9394fe5acc7643f6c263c92db",
              "status": "affected",
              "version": "e15e51384a423be31318b3c9c7d612a1aae661fd",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "unaffected",
          "product": "curl",
          "vendor": "curl",
          "versions": [
            {
              "status": "affected",
              "version": "8.19.0"
            },
            {
              "status": "affected",
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            },
            {
              "status": "affected",
              "version": "8.17.0"
            },
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            {
              "status": "affected",
              "version": "8.11.1"
            },
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              "status": "affected",
              "version": "8.11.0"
            },
            {
              "status": "affected",
              "version": "8.10.1"
            },
            {
              "status": "affected",
              "version": "8.10.0"
            },
            {
              "status": "affected",
              "version": "8.9.1"
            },
            {
              "status": "affected",
              "version": "8.9.0"
            },
            {
              "status": "affected",
              "version": "8.8.0"
            },
            {
              "status": "affected",
              "version": "8.7.1"
            },
            {
              "status": "affected",
              "version": "8.7.0"
            },
            {
              "status": "affected",
              "version": "8.6.0"
            },
            {
              "status": "affected",
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            },
            {
              "status": "affected",
              "version": "8.4.0"
            },
            {
              "status": "affected",
              "version": "8.3.0"
            },
            {
              "status": "affected",
              "version": "8.2.1"
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            {
              "status": "affected",
              "version": "8.2.0"
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            {
              "status": "affected",
              "version": "8.1.2"
            },
            {
              "status": "affected",
              "version": "8.1.1"
            },
            {
              "status": "affected",
              "version": "8.1.0"
            },
            {
              "status": "affected",
              "version": "8.0.1"
            },
            {
              "status": "affected",
              "version": "8.0.0"
            },
            {
              "status": "affected",
              "version": "7.88.1"
            },
            {
              "status": "affected",
              "version": "7.88.0"
            },
            {
              "status": "affected",
              "version": "7.87.0"
            },
            {
              "status": "affected",
              "version": "7.86.0"
            },
            {
              "status": "affected",
              "version": "7.85.0"
            },
            {
              "status": "affected",
              "version": "7.84.0"
            },
            {
              "status": "affected",
              "version": "7.83.1"
            },
            {
              "status": "affected",
              "version": "7.83.0"
            },
            {
              "status": "affected",
              "version": "7.82.0"
            },
            {
              "status": "affected",
              "version": "7.81.0"
            },
            {
              "status": "affected",
              "version": "7.80.0"
            },
            {
              "status": "affected",
              "version": "7.79.1"
            },
            {
              "status": "affected",
              "version": "7.79.0"
            },
            {
              "status": "affected",
              "version": "7.78.0"
            },
            {
              "status": "affected",
              "version": "7.77.0"
            },
            {
              "status": "affected",
              "version": "7.76.1"
            },
            {
              "status": "affected",
              "version": "7.76.0"
            },
            {
              "status": "affected",
              "version": "7.75.0"
            },
            {
              "status": "affected",
              "version": "7.74.0"
            },
            {
              "status": "affected",
              "version": "7.73.0"
            },
            {
              "status": "affected",
              "version": "7.72.0"
            },
            {
              "status": "affected",
              "version": "7.71.1"
            },
            {
              "status": "affected",
              "version": "7.71.0"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "finder",
          "value": "Muhamad Arga Reksapati"
        },
        {
          "lang": "en",
          "type": "remediation developer",
          "value": "Daniel Stenberg"
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Using libcurl, when a custom `Host:` header is first set for an HTTP request\nand a second request is subsequently done using the same *easy handle* but\nwithout the custom `Host:` header set, the second request would use stale\ninformation and pass on cookies meant for the first host in the second\nrequest. Leak them."
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-346",
              "description": "Origin Validation Error",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-15T06:03:04.059Z",
        "orgId": "2499f714-1537-4658-8207-48ae4bb9eae9",
        "shortName": "curl"
      },
      "references": [
        {
          "url": "https://curl.se/docs/CVE-2026-6276.json"
        },
        {
          "url": "https://curl.se/docs/CVE-2026-6276.html"
        },
        {
          "url": "https://hackerone.com/reports/3671818"
        }
      ],
      "title": "stale custom cookie host causes cookie leak",
      "x_generator": {
        "engine": "cvelib 1.8.0"
      },
      "x_osv": {
        "affected": [
          {
            "ranges": [
              {
                "events": [
                  {
                    "introduced": "7.71.0"
                  },
                  {
                    "fixed": "8.14.2"
                  },
                  {
                    "introduced": "8.15.0"
                  },
                  {
                    "fixed": "8.16.1"
                  },
                  {
                    "introduced": "8.17.0"
                  },
                  {
                    "fixed": "8.20.0"
                  }
                ],
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              },
              {
                "events": [
                  {
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                  },
                  {
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                  }
                ],
                "repo": "https://github.com/curl/curl.git",
                "type": "GIT"
              }
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              "8.4.0",
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              "8.2.0",
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              "8.0.1",
              "8.0.0",
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              "7.88.0",
              "7.87.0",
              "7.86.0",
              "7.85.0",
              "7.84.0",
              "7.83.1",
              "7.83.0",
              "7.82.0",
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              "7.77.0",
              "7.76.1",
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              "7.74.0",
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              "7.72.0",
              "7.71.1",
              "7.71.0"
            ]
          }
        ],
        "aliases": [
          "CVE-2026-6276"
        ],
        "credits": [
          {
            "name": "Muhamad Arga Reksapati",
            "type": "finder"
          },
          {
            "name": "Daniel Stenberg",
            "type": "remediation developer"
          }
        ],
        "database_specific": {
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            "desc": "Origin Validation Error",
            "id": "CWE-346"
          },
          "URL": "https://curl.se/docs/CVE-2026-6276.json",
          "affects": "lib",
          "issue": "https://hackerone.com/reports/3671818",
          "last_affected": "8.19.0",
          "package": "curl",
          "severity": "Low",
          "www": "https://curl.se/docs/CVE-2026-6276.html"
        },
        "details": "Using libcurl, when a custom `Host:` header is first set for an HTTP request\nand a second request is subsequently done using the same *easy handle* but\nwithout the custom `Host:` header set, the second request would use stale\ninformation and pass on cookies meant for the first host in the second\nrequest. Leak them.",
        "id": "CURL-CVE-2026-6276",
        "modified": "2026-09-07T10:34:51.00Z",
        "published": "2026-04-29T08:00:00.00Z",
        "schema_version": "1.5.0",
        "summary": "stale custom cookie host causes cookie leak"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "2499f714-1537-4658-8207-48ae4bb9eae9",
    "assignerShortName": "curl",
    "cveId": "CVE-2026-6276",
    "datePublished": "2026-05-13T08:28:19.273Z",
    "dateReserved": "2026-04-14T14:01:54.772Z",
    "dateUpdated": "2026-09-15T06:03:04.059Z",
    "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.

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.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

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GHSA-2JC6-HC33-HV48

CVE-2026-6276 (GCVE-0-2026-6276)

Tags

Sightings

Nomenclature

Related by attack behaviour