CVE-2026-114618

{
  "id": "CVE-2026-114618",
  "sourceIdentifier": "[email protected]",
  "published": "2026-10-22T22:18:04.747",
  "lastModified": "2026-10-29T14:53:01.947",
  "vulnStatus": "Analyzed",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Authlib is a Python library which builds OAuth and OpenID Connect servers. Prior to 1.9.0, the default RFC 7523 JWTBearerGrant.get_audiences() returns an empty list, causing JWTBearerGrant.verify_claims() to require only that an aud claim exists without matching the current authorization server. An attacker holding a legitimate assertion for another service can present it to a server that shares the signing key and uses the default grant, obtaining an access token across a trust boundary. Implementations that override get_audiences() with the server's valid audience identifiers are not affected. This issue is fixed in version 1.9.0."
    }
  ],
  "affected": [
    {
      "source": "[email protected]",
      "affectedData": [
        {
          "vendor": "authlib",
          "product": "authlib",
          "versions": [
            {
              "version": "< 1.9.0",
              "status": "affected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "[email protected]",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N",
          "baseScore": 6.8,
          "baseSeverity": "MEDIUM",
          "attackVector": "NETWORK",
          "attackComplexity": "HIGH",
          "privilegesRequired": "LOW",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "availabilityImpact": "NONE"
        },
        "exploitabilityScore": 1.6,
        "impactScore": 5.2
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-10-29T12:28:44.727870Z",
          "id": "CVE-2026-114618",
          "options": [
            {
              "exploitation": "poc"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
  },
  "weaknesses": [
    {
      "source": "[email protected]",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-287"
        },
        {
          "lang": "en",
          "value": "CWE-1188"
        }
      ]
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "operator": "OR",
          "negate": false,
          "cpeMatch": [
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:a:authlib:authlib:*:*:*:*:*:*:*:*",
              "versionEndExcluding": "1.9.0",
              "matchCriteriaId": "BA8E921E-7ECA-48FD-91C8-B98A9513EAB4"
            }
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        }
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    }
  ],
  "references": [
    {
      "url": "https://github.com/authlib/authlib/commit/e3bd41cb29dcfee434453b135ffb487884baeedf",
      "source": "[email protected]",
      "tags": [
        "Patch"
      ]
    },
    {
      "url": "https://github.com/authlib/authlib/pull/945",
      "source": "[email protected]",
      "tags": [
        "Patch"
      ]
    },
    {
      "url": "https://github.com/authlib/authlib/releases/tag/v1.9.0",
      "source": "[email protected]",
      "tags": [
        "Release Notes"
      ]
    },
    {
      "url": "https://github.com/authlib/authlib/security/advisories/GHSA-fch4-3c6x-j4gc",
      "source": "[email protected]",
      "tags": [
        "Exploit",
        "Vendor Advisory"
      ]
    },
    {
      "url": "https://github.com/authlib/authlib/security/advisories/GHSA-fch4-3c6x-j4gc",
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "tags": [
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        "Vendor Advisory"
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}