Vulnerability-Lookup

ubuntu-cve-2026-69248

Vulnerability from osv_ubuntu

Published

2026-08-03 22:16

Modified

2026-09-10 19:31

Summary

Details

cryptography is a package designed to expose cryptographic primitives and recipes to Python developers. Prior to 49.0.0, if an intermediate constrained CA permits the DNS name foo.example.com, and the leaf certificate has a wildcard in its DNS SAN of .example.com, python-cryptography's verifier accepts which allows escaping outside of the permitted names. The core issue is in DNSConstraint::matches, where a wildcard pattern was treated as matching a more-specific permitted constraint even though .example.com can expand to sibling names such as bar.example.com outside foo.example.com. This allows acceptance of an invalid certificate chain. This issue is fixed in 49.0.0.

Severity

6.9 (Medium)


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

N/A (UNKNOWN)


                    
                      medium

References

URL

Type

	https://ubuntu.com/security/CVE-2026-69248	REPORT
	https://www.cve.org/CVERecord?id=CVE-2026-69248	REPORT
	https://github.com/pyca/cryptography/security/adv…	REPORT
	https://github.com/pyca/cryptography/pull/14888	REPORT
	https://github.com/pyca/cryptography/commit/4d035…	REPORT

JSON

To clipboard

{
  "affected": [
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "python3-cryptography",
            "binary_version": "46.0.5-1ubuntu2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:26.04:LTS",
        "name": "python-cryptography",
        "purl": "pkg:deb/ubuntu/python-cryptography@46.0.5-1ubuntu2?arch=source\u0026distro=resolute"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "43.0.0-1ubuntu1",
        "46.0.1-1ubuntu2",
        "46.0.5-1ubuntu1",
        "46.0.5-1ubuntu2"
      ]
    }
  ],
  "aliases": [],
  "details": "cryptography is a package designed to expose cryptographic primitives and recipes to Python developers. Prior to 49.0.0, if an intermediate constrained CA permits the DNS name foo.example.com, and the leaf certificate has a wildcard in its DNS SAN of *.example.com, python-cryptography\u0027s verifier accepts which allows escaping outside of the permitted names. The core issue is in DNSConstraint::matches, where a wildcard pattern was treated as matching a more-specific permitted constraint even though *.example.com can expand to sibling names such as bar.example.com outside foo.example.com. This allows acceptance of an invalid certificate chain. This issue is fixed in 49.0.0.",
  "id": "UBUNTU-CVE-2026-69248",
  "modified": "2026-09-10T19:31:38Z",
  "published": "2026-08-03T22:16:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-69248"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-69248"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/pyca/cryptography/security/advisories/GHSA-m2h6-j472-rp4c"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/pyca/cryptography/pull/14888"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/pyca/cryptography/commit/4d035a4225965edeffd312079a510ef25fcfdcb2"
    }
  ],
  "related": [],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N/E:P",
      "type": "CVSS_V4"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2026-69248"
  ]
}

CVE-2026-69248 (GCVE-0-2026-69248)

Vulnerability from cvelistv5 – Published: 2026-08-03 21:21 – Updated: 2026-09-02 13:26

Title

python-cryptography verifier accepts wildcard DNS names allowing escape from permittedSubtrees

Summary

cryptography is a package designed to expose cryptographic primitives and recipes to Python developers. In versions 45.0.0 through 48.0.0, if an intermediate constrained CA permits the DNS name foo.example.com, and the leaf certificate has a wildcard in its DNS SAN of *.example.com, python-cryptography's verifier accepts which allows escaping outside of the permitted names. The core issue is in DNSConstraint::matches, where a wildcard pattern was treated as matching a more-specific permitted constraint even though *.example.com can expand to sibling names such as bar.example.com outside foo.example.com. This allows acceptance of an invalid certificate chain. This issue is fixed in 49.0.0.

Severity

6.9 (Medium)


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

SSVC

Exploitation: poc Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-08-04 13:34 UTC

CWE

CWE-295 - Improper Certificate Validation

Assigner

GitHub_M mitre root

References

3 references

URL	Tags
https://github.com/pyca/cryptography/security/adv…	x_refsource_CONFIRM
https://github.com/pyca/cryptography/pull/14888	x_refsource_MISC
https://github.com/pyca/cryptography/commit/4d035…	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
pyca	cryptography	Affected: < 49.0.0

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-69248",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-08-04T13:34:32.304052Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-08-04T15:04:51.587Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "references": [
          {
            "tags": [
              "exploit"
            ],
            "url": "https://github.com/pyca/cryptography/security/advisories/GHSA-m2h6-j472-rp4c"
          }
        ],
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "cryptography",
          "vendor": "pyca",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 49.0.0"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "cryptography is a package designed to expose cryptographic primitives and recipes to Python developers. In versions 45.0.0 through 48.0.0, if an intermediate constrained CA permits the DNS name foo.example.com, and the leaf certificate has a wildcard in its DNS SAN of *.example.com, python-cryptography\u0027s verifier accepts which allows escaping outside of the permitted names. The core issue is in DNSConstraint::matches, where a wildcard pattern was treated as matching a more-specific permitted constraint even though *.example.com can expand to sibling names such as bar.example.com outside foo.example.com. This allows acceptance of an invalid certificate chain. This issue is fixed in 49.0.0."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "attackComplexity": "LOW",
            "attackRequirements": "PRESENT",
            "attackVector": "NETWORK",
            "baseScore": 6.9,
            "baseSeverity": "MEDIUM",
            "privilegesRequired": "NONE",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "NONE",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N/E:P",
            "version": "4.0",
            "vulnAvailabilityImpact": "NONE",
            "vulnConfidentialityImpact": "LOW",
            "vulnIntegrityImpact": "HIGH"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-295",
              "description": "CWE-295: Improper Certificate Validation",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-02T13:26:35.057Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/pyca/cryptography/security/advisories/GHSA-m2h6-j472-rp4c",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/pyca/cryptography/security/advisories/GHSA-m2h6-j472-rp4c"
        },
        {
          "name": "https://github.com/pyca/cryptography/pull/14888",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/pyca/cryptography/pull/14888"
        },
        {
          "name": "https://github.com/pyca/cryptography/commit/4d035a4225965edeffd312079a510ef25fcfdcb2",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/pyca/cryptography/commit/4d035a4225965edeffd312079a510ef25fcfdcb2"
        }
      ],
      "source": {
        "advisory": "GHSA-m2h6-j472-rp4c",
        "discovery": "UNKNOWN"
      },
      "title": "python-cryptography verifier accepts wildcard DNS names allowing escape from permittedSubtrees"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-69248",
    "datePublished": "2026-08-03T21:21:43.710Z",
    "dateReserved": "2026-08-03T19:54:19.852Z",
    "dateUpdated": "2026-09-02T13:26:35.057Z",
    "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.