Vulnerability in lemur (CVE-2026-71317)
Summary
Vulnerability in lemur (CVE-2026-71317). Data can be tampered with by attackers. Exploitable via POST /api/1/authorities. Mitigation: upgrade to 1.9.3 or later.
Original description
The description as published by the source.
Summary
Repo under test: https://github.com/Netflix/lemur
When ADMIN_ONLY_AUTHORITY_CREATION=False (an explicitly supported and documented configuration), POST /api/1/authorities with type=subca never verifies that the caller holds AuthorityPermission on the supplied parent authority. The parent field is resolved by AssociatedAuthoritySchema via a raw fetch_objects(Authority, data) lookup, then passed straight through service.create → mint → cryptography-issuer.create_authority, which loads options["parent"].authority_certificate.private_key and signs a brand-new intermediate CA on the caller's behalf.
Any authenticated non-read-only user can therefore mint a sub-CA chained to any internal root whose private key Lemur holds — including roots they hold no role on — attach a role they already belong to, and immediately issue or offline-sign trusted leaf certificates for arbitrary names.
Affected route
POST /api/1/authorities (with type=subca)
Affected code
lemur/authorities/views.py:231— gates only onAuthorityCreatorPermission()+StrictRolePermission(); noAuthorityPermissionondata['parent']lemur/authorities/schemas.py:58—parent = fields.Nested(AssociatedAuthoritySchema);validate_subcaonly checks presence- [
lemur/schemas.py:107](https://github.com/Netf…
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-2026-71317 has been found in lemur.
Attackers can target a specific entry point like POST /api/1/authorities over the network to misuse the product.
Data can be tampered with by attackers. CVSS score: 6.5/10.
What to do: upgrade lemur to 1.9.3 or later.
If unsure, ask your IT team or search "lemur CVE-2026-71317" on the vendor's site.
CVE-2026-71317 (lemur) — CWE-862 / CVSS v3 6.5
Attack vector: local / no user interaction
Attack surface: POST /api/1/authorities / POST /api/1/certificates / AuthorityPermission / parent
Patched: 1.9.3 — 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-862) exists in lemur. Attackers reach the vulnerable code path via POST /api/1/authorities.
Check the vendor advisory for the affected versions of lemur. Attack surface: POST /api/1/authorities / POST /api/1/certificates / AuthorityPermission / parent.
Severity: Medium (CVSS 6.5/10). Data can be tampered with by attackers.
Update to 1.9.3.
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/1/authorities requests with malformed payloads or SQL meta-characters. Run grep -r 'lemur' . 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 'lemur' . | 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
lemur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/1/authorities' /var/log/nginx/access.log | grep -E '(unusual_payload|sqli_pattern)'アクセスログで
POST /api/1/authorities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 lemur to 1.9.3ステージング環境で 1.9.3 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/1/authorities 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
- advisory github.com
- advisory nvd.nist.gov
- package github.com
- package pypi.org
- web github.com
- web github.com
- web github.com