liboauth2 — security advisory

{
  "id": "de00e0728ff8db4e6176baaeb70fa0853e52cf666c479cb784c93bf8bddd29a8",
  "url": "https://osv.dev/vulnerability/DEBIAN-CVE-2026-54430",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "DEBIAN-CVE-2026-54430",
    "summary": "liboauth2 is vulnerable to Server-Side Request Forgery in oauth2_jose_jwks_aws_alb_resolve() function. The AWS ALB verifier reads both signer and kid from the unverified JWT header. If signer matches the configured ARN, kid is appended to alb_base_url without URL encoding or path sanitization, and the HTTP GET is issued before signature verification. This allows an attacker to force the server to send a GET request to an attacker-chosen internal path. This issue was fixed in version 2.3.0",
    "evidence": "osv:DEBIAN-CVE-2026-54430",
    "products": [
      {
        "name": {
          "value": "liboauth2",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": [
          {
            "value": "2.1.0-2",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "2.1.1-1",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "2.2.0-1",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "2.2.0-2",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "2.2.1-1",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "2.3.0-1",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "2.4.0-1",
            "evidence": "/affected/0/versions"
          }
        ]
      },
      {
        "name": {
          "value": "liboauth2",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "2.3.0-1",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": [
          {
            "value": "2.1.0-2",
            "evidence": "/affected/1/versions"
          },
          {
            "value": "2.1.1-1",
            "evidence": "/affected/1/versions"
          },
          {
            "value": "2.2.0-1",
            "evidence": "/affected/1/versions"
          },
          {
            "value": "2.2.0-2",
            "evidence": "/affected/1/versions"
          },
          {
            "value": "2.2.1-1",
            "evidence": "/affected/1/versions"
          }
        ]
      }
    ],
    "severity": "medium",
    "structured": {
      "id": "DEBIAN-CVE-2026-54430",
      "aliases": [
        "DEBIAN-CVE-2026-54430"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:L/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"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                }
              ]
            }
          ],
          "package": {
            "name": "liboauth2",
            "purl": "pkg:deb/debian/liboauth2?arch=source&distro=trixie",
            "ecosystem": "Debian:13"
          },
          "versions": [
            "2.1.0-2",
            "2.1.1-1",
            "2.2.0-1",
            "2.2.0-2",
            "2.2.1-1",
            "2.3.0-1",
            "2.4.0-1"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-54430.json"
          },
          "ecosystem_specific": {
            "urgency": "not yet assigned"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "2.3.0-1"
                }
              ]
            }
          ],
          "package": {
            "name": "liboauth2",
            "purl": "pkg:deb/debian/liboauth2?arch=source&distro=forky",
            "ecosystem": "Debian:14"
          },
          "versions": [
            "2.1.0-2",
            "2.1.1-1",
            "2.2.0-1",
            "2.2.0-2",
            "2.2.1-1"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-54430.json"
          },
          "ecosystem_specific": {
            "urgency": "not yet assigned"
          }
        }
      ],
      "modified": "2026-10-26T11:47:37.577336337Z",
      "provider": "osv",
      "upstream": [
        "CVE-2026-54430"
      ],
      "references": [
        "https://security-tracker.debian.org/tracker/CVE-2026-54430"
      ]
    },
    "related_cves": [
      {
        "value": "CVE-2026-54430",
        "evidence": "/upstream"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 450925,
  "published_at": "2026-07-02T11:16:16.423+00:00"
}