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CVE-2026-49852
Authentication Bypass in joserfc (CVE-2026-49852)
Summary
authentication bypass in joserfc (CVE-2026-49852). Risk of unauthorized operations or information disclosure. Exploitable via ``joserfc.jwt.decode``. Mitigation: upgrade to `1.6.8` or later.
AI summary snake-internal / snake-material-v2
A vulnerability tracked as **CVE-2026-49852** has been found in joserfc.
Attackers can target a specific entry point like ``joserfc.jwt.decode`` over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: ?/10.
What to do: upgrade joserfc to **1.6.8** or later.
If unsure, ask your IT team or search "joserfc CVE-2026-49852" on the vendor's site.
CVE-2026-49852 (joserfc) — CWE-287 /
Attack surface: `joserfc.jwt.decode` / `None` / `HMACAlgorithm.sign` / `HMACAlgorithm.verify`
Patched: `1.6.8` — 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.
❓ What is the problem
**authentication bypass** (CWE-287) exists in joserfc. Attackers reach the vulnerable code path via ``joserfc.jwt.decode`` without authentication.
📍 Affected scope
joserfc — . Attack surface: `joserfc.jwt.decode` / `None` / `HMACAlgorithm.sign` / `HMACAlgorithm.verify`.
🔥 Severity
Severity: ?. Risk of unauthorized operations or information disclosure
🔧 How to fix
Update to **1.6.8**.
🛡️ Workaround
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
🔍 Detection
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run `grep -r 'joserfc' .` against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response Actions (7 steps)
Concrete steps and command examples for SOC/SRE teams to execute in order
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1Identify exposure identify
grep -r 'joserfc' . | 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 `joserfc` を grep し、稼働しているサービス・バージョンを把握する。
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6Apply patch patch
Upgrade joserfc to 1.6.8ステージング環境で 1.6.8 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 3 で見つけた異常検知の続報チェックを含めること。
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7Post-deployment verification verify
Confirm patched version is live in production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 3 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
pip
joserfc
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.6.8"}]}]
References
- web https://github.com/authlib/joserfc/security/advisories/GHSA-gg9x-qcx2-xmrh
- web https://github.com/authlib/joserfc/commit/86d00910b2b2d2d07503fee9b572906daefab7f1
- web https://github.com/authlib/joserfc/blob/1ddca8f3c73ff47e3bc3ac06cb0c08a9535677ec/src/joserfc/_rfc7518/jws_algs.py#L62-L70
- web https://github.com/advisories/GHSA-gg9x-qcx2-xmrh