Vikunja: WebSocket authentication ignores server-side session state, so revoked sessions keep receiving live pushes

{
  "id": "de6916b35fb6367e0e6b56ce976b3bd8b264f3402ea63721b7976e750e349987",
  "url": "https://osv.dev/vulnerability/GHSA-4hv6-xc92-j86g",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Vikunja: WebSocket authentication ignores server-side session state, so revoked sessions keep receiving live pushes",
    "summary": "### Summary Vikunja v2.6.0 introduced server-side sessions with revocation semantics: `DELETE /api/v2/user/sessions/{id}` documents \"Revokes a specific session by its UUID\", and enabling TOTP calls `DeleteAllUserSessions` to invalidate all sessions. The WebSocket endpoint accepts any cryptographically valid user JWT without ever resolving its `sid` (session id) claim against the sessions table. A connection authenticated before revocation stays authenticated and continues to receive live pushes indefinitely, and even brand-new WebSocket connections are accepted with a token whose session was deleted. The revocation feature therefore does not cover the WebSocket boundary at all. ### Details User access JWTs carry a session reference: `NewUserJWTAuthtoken` (`pkg/modules/auth/auth.go:188`) sets `claims[\"sid\"] = sessionID`, and the API login-session documentation describes the claim as tying the JWT to a server-side session. On the HTTP side nothing consumes the claim per request either (REST access tokens simply expire after their short TTL, a design the maintainers documented when fixing GHSA-96q5, and refresh tokens are correctly invalidated when the session row is deleted). The WebSocket endpoint `GET /api/v2/ws` authenticates through the first client message. `Connection.handleAuth` (`pkg/websocket/connection.go:168`) validates the token exclusively with `auth.GetUserIDFromToken` (`pkg/modules/auth/auth.go:292`): ```go func GetUserIDFromToken(tokenString string) (int64, erro",
    "evidence": "osv:GHSA-4hv6-xc92-j86g",
    "products": [
      {
        "name": {
          "value": "code.vikunja.io/api",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "2.7.0",
            "evidence": "/affected/0/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "medium",
    "structured": {
      "id": "GHSA-4hv6-xc92-j86g",
      "aliases": [
        "CVE-2026-111917",
        "GHSA-4hv6-xc92-j86g",
        "GO-2026-6715"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "SEMVER",
              "events": [
                {
                  "introduced": "2.3.0"
                },
                {
                  "fixed": "2.7.0"
                }
              ]
            }
          ],
          "package": {
            "name": "code.vikunja.io/api",
            "purl": "pkg:golang/code.vikunja.io/api",
            "ecosystem": "Go"
          },
          "database_specific": {
            "source": "https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/10/GHSA-4hv6-xc92-j86g/GHSA-4hv6-xc92-j86g.json",
            "last_known_affected_version_range": "<= 2.6.0"
          }
        }
      ],
      "modified": "2026-10-27T15:30:05.449149864Z",
      "provider": "osv",
      "references": [
        "https://github.com/go-vikunja/vikunja/security/advisories/GHSA-4hv6-xc92-j86g",
        "https://github.com/go-vikunja/vikunja/commit/46ae98355462acbea451356326146675d3feeaab",
        "https://github.com/go-vikunja/vikunja",
        "https://github.com/go-vikunja/vikunja/releases/tag/v2.7.0"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-613"
        ],
        "severity": "MODERATE",
        "github_reviewed": true,
        "nvd_published_at": null,
        "github_reviewed_at": "2026-10-09T20:57:34Z"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-111917",
        "evidence": "/aliases"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 462571,
  "published_at": "2026-10-09T20:57:34+00:00"
}