Vulnerability-Lookup

UBUNTU-CVE-2026-102268 (CVE-2026-102268)

Vulnerability from osv_ubuntu – Published: 2026-09-28 21:17 – Updated: 2026-09-30 21:41 – Source website

Details

PyJWT is a Python implementation of JSON Web Token standards. Prior to 2.14.0, is_pem_format in jwt/utils.py is affected because is_pem_format does not recognize every PEM representation accepted by the cryptography loader. This occurs when an application mixes HMAC and asymmetric algorithms and supplies a mutated public-key PEM as raw key bytes. As a result, HMACAlgorithm.prepare_key treats the unrecognized asymmetric public key as an HMAC secret. Consequently, an attacker who knows the public key can forge authenticated HMAC tokens. This issue is fixed in version 2.14.0.

Severity

9.1 (Critical)


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

N/A (UNKNOWN)


                    
                      medium

References

URL

Type

	https://ubuntu.com/security/CVE-2026-102268	REPORT
	https://www.cve.org/CVERecord?id=CVE-2026-102268	REPORT
	https://github.com/jpadilla/pyjwt/security/adviso…	REPORT
	https://github.com/jpadilla/pyjwt/commit/8b4e233a…	REPORT
	https://github.com/jpadilla/pyjwt/releases/tag/2.14.0	REPORT

JSON

To clipboard

{
  "affected": [
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "python-jwt",
            "binary_version": "1.3.0-1ubuntu0.1+esm2"
          },
          {
            "binary_name": "python3-jwt",
            "binary_version": "1.3.0-1ubuntu0.1+esm2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:16.04:LTS",
        "name": "pyjwt",
        "purl": "pkg:deb/ubuntu/pyjwt@1.3.0-1ubuntu0.1+esm2?arch=source\u0026distro=esm-infra-legacy/xenial"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.0.0-0ubuntu1",
        "1.3.0-1",
        "1.3.0-1ubuntu0.1",
        "1.3.0-1ubuntu0.1+esm1",
        "1.3.0-1ubuntu0.1+esm2"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "python-jwt",
            "binary_version": "1.5.3+ds1-1ubuntu0.1+esm2"
          },
          {
            "binary_name": "python3-jwt",
            "binary_version": "1.5.3+ds1-1ubuntu0.1+esm2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:18.04:LTS",
        "name": "pyjwt",
        "purl": "pkg:deb/ubuntu/pyjwt@1.5.3+ds1-1ubuntu0.1+esm2?arch=source\u0026distro=esm-infra/bionic"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.4.2-1.1",
        "1.5.3+ds1-1",
        "1.5.3+ds1-1ubuntu0.1",
        "1.5.3+ds1-1ubuntu0.1+esm1",
        "1.5.3+ds1-1ubuntu0.1+esm2"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "python3-jwt",
            "binary_version": "1.7.1-2ubuntu2.1+esm2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:20.04:LTS",
        "name": "pyjwt",
        "purl": "pkg:deb/ubuntu/pyjwt@1.7.1-2ubuntu2.1+esm2?arch=source\u0026distro=esm-infra/focal"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.7.0-2",
        "1.7.1-1",
        "1.7.1-2ubuntu1",
        "1.7.1-2ubuntu2",
        "1.7.1-2ubuntu2.1",
        "1.7.1-2ubuntu2.1+esm1",
        "1.7.1-2ubuntu2.1+esm2"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "python3-jwt",
            "binary_version": "2.3.0-1ubuntu0.4"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:22.04:LTS",
        "name": "pyjwt",
        "purl": "pkg:deb/ubuntu/pyjwt@2.3.0-1ubuntu0.4?arch=source\u0026distro=jammy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.7.1-2ubuntu2",
        "2.1.0-1",
        "2.3.0-1",
        "2.3.0-1ubuntu0.1",
        "2.3.0-1ubuntu0.2",
        "2.3.0-1ubuntu0.3",
        "2.3.0-1ubuntu0.4"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "python3-jwt",
            "binary_version": "2.7.0-1ubuntu0.2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:24.04:LTS",
        "name": "pyjwt",
        "purl": "pkg:deb/ubuntu/pyjwt@2.7.0-1ubuntu0.2?arch=source\u0026distro=noble"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "2.7.0-1",
        "2.7.0-1ubuntu0.1",
        "2.7.0-1ubuntu0.2"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "python3-jwt",
            "binary_version": "2.10.1-4ubuntu1.1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:26.04:LTS",
        "name": "pyjwt",
        "purl": "pkg:deb/ubuntu/pyjwt@2.10.1-4ubuntu1.1?arch=source\u0026distro=resolute"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "2.10.1-2",
        "2.10.1-3",
        "2.10.1-3build1",
        "2.10.1-4",
        "2.10.1-4ubuntu1",
        "2.10.1-4ubuntu1.1"
      ]
    }
  ],
  "aliases": [],
  "details": "PyJWT is a Python implementation of JSON Web Token standards. Prior to 2.14.0, is_pem_format in jwt/utils.py is affected because is_pem_format does not recognize every PEM representation accepted by the cryptography loader. This occurs when an application mixes HMAC and asymmetric algorithms and supplies a mutated public-key PEM as raw key bytes. As a result, HMACAlgorithm.prepare_key treats the unrecognized asymmetric public key as an HMAC secret. Consequently, an attacker who knows the public key can forge authenticated HMAC tokens. This issue is fixed in version 2.14.0.",
  "id": "UBUNTU-CVE-2026-102268",
  "modified": "2026-09-30T21:41:54Z",
  "published": "2026-09-28T21:17:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-102268"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-102268"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/jpadilla/pyjwt/security/advisories/GHSA-ffc3-869f-jxw9"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/jpadilla/pyjwt/commit/8b4e233a22206b34ec1186e912e75c0b2396ac07"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/jpadilla/pyjwt/releases/tag/2.14.0"
    }
  ],
  "related": [],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N",
      "type": "CVSS_V3"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2026-102268"
  ]
}

CVE-2026-102268 (GCVE-0-2026-102268)

Vulnerability from cvelistv5 – Published: 2026-09-28 20:26 – Updated: 2026-09-29 13:59

Title

PyJWT: Asymmetric-PEM detection bypass: whitespace/line-ending-mutated public keys skip the HS/asymmetric confusion guard

Summary

Severity

9.1 (Critical)


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

SSVC

Exploitation: poc Automatable: yes Technical Impact: total

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-09-29 13:59 UTC

CWE

CWE-347 - Improper Verification of Cryptographic Signature

Assigner

GitHub_M mitre root Scorecard

References

3 references

URL	Tags
https://github.com/jpadilla/pyjwt/security/adviso…	x_refsource_CONFIRM
https://github.com/jpadilla/pyjwt/commit/8b4e233a…	x_refsource_MISC
https://github.com/jpadilla/pyjwt/releases/tag/2.14.0	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
jpadilla	pyjwt	Affected: < 2.14.0

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-102268",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-09-29T13:59:05.202281Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-09-29T13:59:11.421Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "references": [
          {
            "tags": [
              "exploit"
            ],
            "url": "https://github.com/jpadilla/pyjwt/security/advisories/GHSA-ffc3-869f-jxw9"
          }
        ],
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "pyjwt",
          "vendor": "jpadilla",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 2.14.0"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "PyJWT is a Python implementation of JSON Web Token standards. Prior to 2.14.0, is_pem_format in jwt/utils.py is affected because is_pem_format does not recognize every PEM representation accepted by the cryptography loader. This occurs when an application mixes HMAC and asymmetric algorithms and supplies a mutated public-key PEM as raw key bytes. As a result, HMACAlgorithm.prepare_key treats the unrecognized asymmetric public key as an HMAC secret. Consequently, an attacker who knows the public key can forge authenticated HMAC tokens. This issue is fixed in version 2.14.0."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 9.1,
            "baseSeverity": "CRITICAL",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-347",
              "description": "CWE-347: Improper Verification of Cryptographic Signature",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-28T20:26:13.674Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/jpadilla/pyjwt/security/advisories/GHSA-ffc3-869f-jxw9",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/jpadilla/pyjwt/security/advisories/GHSA-ffc3-869f-jxw9"
        },
        {
          "name": "https://github.com/jpadilla/pyjwt/commit/8b4e233a22206b34ec1186e912e75c0b2396ac07",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/jpadilla/pyjwt/commit/8b4e233a22206b34ec1186e912e75c0b2396ac07"
        },
        {
          "name": "https://github.com/jpadilla/pyjwt/releases/tag/2.14.0",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/jpadilla/pyjwt/releases/tag/2.14.0"
        }
      ],
      "source": {
        "advisory": "GHSA-ffc3-869f-jxw9",
        "discovery": "UNKNOWN"
      },
      "title": "PyJWT: Asymmetric-PEM detection bypass: whitespace/line-ending-mutated public keys skip the HS/asymmetric confusion guard"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-102268",
    "datePublished": "2026-09-28T20:26:13.674Z",
    "dateReserved": "2026-09-28T20:11:16.658Z",
    "dateUpdated": "2026-09-29T13:59:11.421Z",
    "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.
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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

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.

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UBUNTU-CVE-2026-102268 (CVE-2026-102268)

CVE-2026-102268 (GCVE-0-2026-102268)

Tags

Sightings

Nomenclature

Related by attack behaviour