Vulnerability-Lookup

OESA-2026-3457 (CVE-2026-69249)

Vulnerability from osv_openeuler – Published: 2026-08-20 10:00 – Updated: 2026-08-20 10:00 – Source website

Summary

python-cryptography security update

Details

cryptography is a package designed to expose cryptographic primitives and recipes to Python developers.

Security Fix(es):

python-cryptography is a package designed to expose cryptographic primitives and recipes to Python developers. Prior to 49.0.0, when resolving invalid certificate chains that include duplicate copies of self-signed certificates, the processing recursively invokes the same candidate, leading to an exponential blowup. Although the limitation that the chain depth cannot exceed a specified maximum depth prevents unbounded recursion and guarantees termination, an attacker-controlled certificate chain can lead the processing to easily take more than 5s to reject in testing. This amplification could form the basis for a resource exhaustion denial of service attack. The core issue arises in the recursive nature of build_chain_inner, which does not de-duplicate against previously analyzed candidates. As the correctness of validation is not affected, the integrity of a system cannot be compromised through this vector, only its availability. This issue is fixed in 49.0.0.(CVE-2026-69249)

Severity

8.7 (High)


                    
                      CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

References

URL

Type

	https://www.openeuler.org/zh/security/security-bu…	ADVISORY
	https://nvd.nist.gov/vuln/detail/CVE-2026-69249	ADVISORY

JSON

To clipboard

{
  "affected": [
    {
      "ecosystem_specific": {
        "aarch64": [
          "python-cryptography-debuginfo-42.0.2-10.oe2403sp3.aarch64.rpm",
          "python-cryptography-debugsource-42.0.2-10.oe2403sp3.aarch64.rpm",
          "python3-cryptography-42.0.2-10.oe2403sp3.aarch64.rpm"
        ],
        "noarch": [
          "python-cryptography-help-42.0.2-10.oe2403sp3.noarch.rpm"
        ],
        "src": [
          "python-cryptography-42.0.2-10.oe2403sp3.src.rpm"
        ],
        "x86_64": [
          "python-cryptography-debuginfo-42.0.2-10.oe2403sp3.x86_64.rpm",
          "python-cryptography-debugsource-42.0.2-10.oe2403sp3.x86_64.rpm",
          "python3-cryptography-42.0.2-10.oe2403sp3.x86_64.rpm"
        ]
      },
      "package": {
        "ecosystem": "openEuler:24.03-LTS-SP3",
        "name": "python-cryptography",
        "purl": "pkg:rpm/openEuler/python-cryptography\u0026distro=openEuler-24.03-LTS-SP3"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "42.0.2-10.oe2403sp3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "severity": "High"
  },
  "details": "cryptography is a package designed to expose cryptographic primitives and recipes to Python developers.\r\n\r\nSecurity Fix(es):\n\npython-cryptography is a package designed to expose cryptographic primitives and recipes to Python developers. Prior to 49.0.0, when resolving invalid certificate chains that include duplicate copies of self-signed certificates, the processing recursively invokes the same candidate, leading to an exponential blowup. Although the limitation that the chain depth cannot exceed a specified maximum depth prevents unbounded recursion and guarantees termination, an attacker-controlled certificate chain can lead the processing to easily take more than 5s to reject in testing. This amplification could form the basis for a resource exhaustion denial of service attack. The core issue arises in the recursive nature of build_chain_inner, which does not de-duplicate against previously analyzed candidates. As the correctness of validation is not affected, the integrity of a system cannot be compromised through this vector, only its availability. This issue is fixed in 49.0.0.(CVE-2026-69249)",
  "id": "OESA-2026-3457",
  "modified": "2026-08-20T10:00:02Z",
  "published": "2026-08-20T10:00:02Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.openeuler.org/zh/security/security-bulletins/detail/?id=openEuler-SA-2026-3457"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-69249"
    }
  ],
  "schema_version": "1.7.2",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
      "type": "CVSS_V4"
    }
  ],
  "summary": "python-cryptography security update",
  "upstream": [
    "CVE-2026-69249"
  ]
}

CVE-2026-69249 (GCVE-0-2026-69249)

Vulnerability from cvelistv5 – Published: 2026-08-03 21:26 – Updated: 2026-09-04 21:20

Title

python-cryptography: Duplicate self-signed intermediates can cause exponential path-building

Summary

python-cryptography is a package designed to expose cryptographic primitives and recipes to Python developers. In versions 42.0.0 through 48.0.0, when resolving invalid certificate chains that include duplicate copies of self-signed certificates, the processing recursively invokes the same candidate, leading to an exponential blowup. Although the limitation that the chain depth cannot exceed a specified maximum depth prevents unbounded recursion and guarantees termination, an attacker-controlled certificate chain can lead the processing to easily take more than 5s to reject in testing. This amplification could form the basis for a resource exhaustion denial of service attack. The core issue arises in the recursive nature of build_chain_inner, which does not de-duplicate against previously analyzed candidates. As the correctness of validation is not affected, the integrity of a system cannot be compromised through this vector, only its availability. This issue is fixed in 49.0.0.

Severity

8.7 (High)


                        
                          CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

SSVC

Exploitation: poc Automatable: yes Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-08-04 14:08 UTC

CWE

CWE-400 - Uncontrolled Resource Consumption

Assigner

GitHub_M mitre root

References

5 references

URL	Tags
https://github.com/pyca/cryptography/security/adv…	x_refsource_CONFIRM
https://github.com/pyca/cryptography/pull/14960	x_refsource_MISC
https://github.com/pyca/cryptography/commit/3763aa79b	x_refsource_MISC
https://github.com/pyca/cryptography/commit/4a12c…	x_refsource_MISC
https://github.com/pypa/advisory-database/tree/ma…	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
pyca	cryptography	Affected: >= 42.0.0, < 49.0.0

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-69249",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-08-04T14:08:23.254769Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-08-04T14:08:58.056Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "references": [
          {
            "tags": [
              "exploit"
            ],
            "url": "https://github.com/pyca/cryptography/security/advisories/GHSA-jwv3-5hgf-82ww"
          }
        ],
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "cryptography",
          "vendor": "pyca",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 42.0.0, \u003c 49.0.0"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "python-cryptography is a package designed to expose cryptographic primitives and recipes to Python developers. In versions 42.0.0 through 48.0.0, when resolving invalid certificate chains that include duplicate copies of self-signed certificates, the processing recursively invokes the same candidate, leading to an exponential blowup. Although the limitation that the chain depth cannot exceed a specified maximum depth prevents unbounded recursion and guarantees termination, an attacker-controlled certificate chain can lead the processing to easily take more than 5s to reject in testing. This amplification could form the basis for a resource exhaustion denial of service attack. The core issue arises in the recursive nature of build_chain_inner, which does not de-duplicate against previously analyzed candidates. As the correctness of validation is not affected, the integrity of a system cannot be compromised through this vector, only its availability. This issue is fixed in 49.0.0."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "attackComplexity": "LOW",
            "attackRequirements": "NONE",
            "attackVector": "NETWORK",
            "baseScore": 8.7,
            "baseSeverity": "HIGH",
            "privilegesRequired": "NONE",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "NONE",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "HIGH",
            "vulnConfidentialityImpact": "NONE",
            "vulnIntegrityImpact": "NONE"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-400",
              "description": "CWE-400: Uncontrolled Resource Consumption",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-04T21:20:32.666Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/pyca/cryptography/security/advisories/GHSA-jwv3-5hgf-82ww",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/pyca/cryptography/security/advisories/GHSA-jwv3-5hgf-82ww"
        },
        {
          "name": "https://github.com/pyca/cryptography/pull/14960",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/pyca/cryptography/pull/14960"
        },
        {
          "name": "https://github.com/pyca/cryptography/commit/3763aa79b",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/pyca/cryptography/commit/3763aa79b"
        },
        {
          "name": "https://github.com/pyca/cryptography/commit/4a12cf49675a184e47f912b00b04f3a629283582",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/pyca/cryptography/commit/4a12cf49675a184e47f912b00b04f3a629283582"
        },
        {
          "name": "https://github.com/pypa/advisory-database/tree/main/vulns/cryptography/PYSEC-2026-3553.yaml",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/pypa/advisory-database/tree/main/vulns/cryptography/PYSEC-2026-3553.yaml"
        }
      ],
      "source": {
        "advisory": "GHSA-jwv3-5hgf-82ww",
        "discovery": "UNKNOWN"
      },
      "title": "python-cryptography: Duplicate self-signed intermediates can cause exponential path-building"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-69249",
    "datePublished": "2026-08-03T21:26:45.826Z",
    "dateReserved": "2026-08-03T19:54:19.852Z",
    "dateUpdated": "2026-09-04T21:20:32.666Z",
    "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.
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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