Privilege Escalation in code.vikunja.io/api (CVE-2026-57458)
Summary
Vulnerability in code.vikunja.io/api (CVE-2026-57458). Confidential information can be exposed externally. Exploitable via POST /api/v1/oauth/authorize. Mitigation: upgrade to 2.4.0 or later.
Original description
The description as published by the source.
Summary
A scoped API token can bypass its declared permissions by using the OAuth authorization flow to mint normal session credentials.
A token limited to:
{"oauth":["authorize"]}
can call /api/v1/oauth/authorize, receive an OAuth authorization code, exchange it at /api/v1/oauth/token, and obtain a normal bearer JWT plus refresh token. The resulting credentials are not restricted by the original API-token permissions.
Affected Component
- Scoped API tokens
- OAuth authorization flow
POST /api/v1/oauth/authorizePOST /api/v1/oauth/token
Impact
A narrowly scoped API token with only oauth.authorize can be converted into normal session credentials for the same user.
This bypasses the intended API-token permission boundary. An attacker who obtains or is delegated such a limited token can mint a normal JWT and refresh token, then access routes outside the original token scope.
Runtime validation showed that the original scoped token could not access GET /api/v1/user, but the minted OAuth access token could access:
GET /api/v1/userGET /api/v1/projects
No cross-user access, privilege escalation to admin, or access to another account was validated.
Technical Details
The issue is caused by an authentication-context mismatch between scoped API-token authentication and OAuth authorization-code issuance.
The vulnerable chain is:
- A scoped API token authenticates the request and sets the current user context.
- `/api/v1/o…
Source: GitHub Security Advisories (Global) NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-57458 has been found in code.vikunja.io/api.
Attackers can target a specific entry point like POST /api/v1/oauth/authorize over the network to misuse the product.
Confidential information can be exposed externally. CVSS score: 8.1/10.
What to do: upgrade code.vikunja.io/api to 2.4.0 or later.
If unsure, ask your IT team or search "code.vikunja.io/api CVE-2026-57458" on the vendor's site.
CVE-2026-57458 (code.vikunja.io/api) — CWE-269 / CVSS v3 8.1
Attack vector: remote (network-reachable) / no user interaction
Attack surface: POST /api/v1/oauth/authorize / POST /api/v1/oauth/token / GET /api/v1/user / GET /api/v1/projects
Patched: 2.4.0 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-269) exists in code.vikunja.io/api. Attackers reach the vulnerable code path via POST /api/v1/oauth/authorize.
Check the vendor advisory for the affected versions of code.vikunja.io/api. Attack surface: POST /api/v1/oauth/authorize / POST /api/v1/oauth/token / GET /api/v1/user / GET /api/v1/projects.
Severity: High (CVSS 8.1/10). Confidential information can be exposed externally.
Update to 2.4.0.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual POST /api/v1/oauth/authorize requests with malformed payloads or SQL meta-characters. Run grep -r 'code.vikunja.io/api' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'code.vikunja.io/api' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
code.vikunja.io/apiを grep し、稼働しているサービス・バージョンを把握する。 -
2Hunt for indicators of compromise detect
grep 'POST /api/v1/oauth/authorize' /var/log/nginx/access.log | grep -E '(unusual_payload|sqli_pattern)'アクセスログで
POST /api/v1/oauth/authorizeへの異常なリクエスト (不正な認証ヘッダ・SQLメタ文字)を過去 30〜90日分捜索。WAF/SIEM があれば該当パスのアラート発火履歴を確認。 -
3Apply patch patch
Upgrade code.vikunja.io/api to 2.4.0ステージング環境で 2.4.0 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスと、Step 2 で見つけた異常検知の続報チェックを含めること。
-
4Post-deployment verification verify
Replay attack against POST /api/v1/oauth/authorize on staging to confirm patch closes the vectorパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番では Step 2 と同じログクエリでアラート再発が無いか継続監視。
Affected packages
References
- package github.com
- web github.com
- web github.com
- web github.com
- web github.com