USN-8916-2 (UBUNTU-CVE-2026-102266)

Vulnerability from osv_ubuntu – Published: 2026-10-15 06:24 – Updated: 2026-10-27 09:03 – Source website
VLAI
Summary
pyjwt vulnerabilities
Details

USN-8916-1 fixed vulnerabilities in PyJWT. This update provides the corresponding fix for PyJWT on Ubuntu 26.10.

Original advisory details:

YuSung Han discovered that PyJWT did not properly validate certain JWK keys when performing HMAC verification. An attacker could possibly use this issue to forge authentication tokens. (CVE-2026-102266)

Rohan Das discovered that PyJWT incorrectly handled redirects when fetching key sets. A remote attacker could possibly use this issue to cause PyJWT to disclose sensitive information. (CVE-2026-102267)

It was discovered that PyJWT incorrectly recognized certain PEM representations. An attacker who knew the public key could possibly use this issue to forge authentication tokens. (CVE-2026-102268)

Nuno Lopes discovered that PyJWT incorrectly handled DER public keys when performing HMAC verification. An attacker who knew the public key could possibly use this issue to forge authentication tokens. (CVE-2026-102271)

It was discovered that PyJWT did not properly handle certain JWK keys prefixed with a byte-order mark. An attacker who knew the public key could possibly use this issue to forge authentication tokens. (CVE-2026-102272)

Charles Vosburgh discovered that PyJWT incorrectly handled certain JWK containers when performing HMAC verification. An attacker who knew the public key could possibly use this issue to forge authentication tokens. (CVE-2026-102273)

References
To clipboard 

{
  "affected": [
    {
      "database_specific": {
        "cves_map": {
          "cves": [
            {
              "id": "CVE-2026-102266",
              "severity": [
                {
                  "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N",
                  "type": "CVSS_V3"
                },
                {
                  "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"
                }
              ]
            },
            {
              "id": "CVE-2026-102267",
              "severity": [
                {
                  "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N",
                  "type": "CVSS_V3"
                },
                {
                  "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"
                }
              ]
            },
            {
              "id": "CVE-2026-102268",
              "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"
                }
              ]
            },
            {
              "id": "CVE-2026-102271",
              "severity": [
                {
                  "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N",
                  "type": "CVSS_V3"
                },
                {
                  "score": "medium",
                  "type": "Ubuntu"
                }
              ]
            },
            {
              "id": "CVE-2026-102272",
              "severity": [
                {
                  "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N",
                  "type": "CVSS_V3"
                },
                {
                  "score": "medium",
                  "type": "Ubuntu"
                }
              ]
            },
            {
              "id": "CVE-2026-102273",
              "severity": [
                {
                  "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N",
                  "type": "CVSS_V3"
                },
                {
                  "score": "medium",
                  "type": "Ubuntu"
                }
              ]
            }
          ],
          "ecosystem": "Ubuntu:26.10"
        }
      },
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "python3-jwt",
            "binary_version": "2.13.0-1ubuntu1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:26.10",
        "name": "pyjwt",
        "purl": "pkg:deb/ubuntu/pyjwt@2.13.0-1ubuntu1?arch=source\u0026distro=stonking"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "2.13.0-1ubuntu1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "2.10.1-4ubuntu1",
        "2.12.1-1",
        "2.13.0-1"
      ]
    }
  ],
  "aliases": [],
  "details": "USN-8916-1 fixed vulnerabilities in PyJWT. This update provides the\ncorresponding fix for PyJWT on Ubuntu 26.10.\n\nOriginal advisory details:\n\nYuSung Han discovered that PyJWT did not properly validate certain JWK keys\nwhen performing HMAC verification. An attacker could possibly use this\nissue to forge authentication tokens. (CVE-2026-102266)\n\nRohan Das discovered that PyJWT incorrectly handled redirects when fetching\nkey sets. A remote attacker could possibly use this issue to  cause PyJWT\nto disclose sensitive information. (CVE-2026-102267)\n\nIt was discovered that PyJWT incorrectly recognized certain PEM\nrepresentations. An attacker who knew the public key could possibly use\nthis issue to forge authentication tokens. (CVE-2026-102268)\n\nNuno Lopes discovered that PyJWT incorrectly handled DER public keys when\nperforming HMAC verification. An attacker who knew the public key could\npossibly use this issue to forge authentication tokens. (CVE-2026-102271)\n\nIt was discovered that PyJWT did not properly handle certain JWK keys\nprefixed with a byte-order mark. An attacker who knew the public key could\npossibly use this issue to forge authentication tokens. (CVE-2026-102272)\n\nCharles Vosburgh discovered that PyJWT incorrectly handled certain JWK\ncontainers when performing HMAC verification. An attacker who knew the\npublic key could possibly use this issue to forge authentication tokens.\n(CVE-2026-102273)",
  "id": "USN-8916-2",
  "modified": "2026-10-27T09:03:14Z",
  "published": "2026-10-15T06:24:37Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://ubuntu.com/security/notices/USN-8916-2"
    },
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-102266"
    },
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-102267"
    },
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-102268"
    },
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-102271"
    },
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-102272"
    },
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-102273"
    }
  ],
  "related": [],
  "schema_version": "1.7.0",
  "summary": "pyjwt vulnerabilities",
  "upstream": [
    "UBUNTU-CVE-2026-102266",
    "UBUNTU-CVE-2026-102267",
    "UBUNTU-CVE-2026-102268",
    "UBUNTU-CVE-2026-102271",
    "UBUNTU-CVE-2026-102272",
    "UBUNTU-CVE-2026-102273"
  ]
}



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