Vulnerability details
CVE-2026-71308
Lemur: Unchecked `replaces[]` lets any user silence notifications and hijack auto-rotation for arbitrary certificates
Official description
Lemur manages TLS certificate creation. From 0.5.0 until 1.9.3, certificate create, upload, and edit requests accepted replaces[] or replacements identifiers that AssociatedCertificateSchema resolved with fetch_objects without a CertificatePermission check. Assigning those objects to Certificate.replaces invoked an append listener that disabled the victim certificate notifications and marked it as replaced. The victim was then excluded from get_all_pending_reissue, and certificate_rotate could deploy the attacker certificate to endpoints serving the victim. An authenticated non-read-only user could target certificates for which the user had no ownership or role, suppress lifecycle automation, and cause fleet-wide TLS disruption or unauthorized substitution. The fix authorizes every referenced replacement certificate before mutation. This issue is fixed in version 1.9.3.
CVSS scores
| Score | Version | Source | Vector |
|---|---|---|---|
| 8.1High | 3.1 | CVEProject cvelistV5 (CNA) (GitHub_M) | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H |
Affected products
| Vendor | Product | Versions | Source |
|---|---|---|---|
| Netflix | lemur | >= 0.5.0, < 1.9.3 | CVEProject cvelistV5 (CNA) |
References and advisories
3- https://github.com/Netflix/lemur/commit/286874535160952143b0afe2d356642669f9d4c6 x_refsource_MISC
- https://github.com/Netflix/lemur/releases/tag/v1.9.3 x_refsource_MISC
- https://github.com/Netflix/lemur/security/advisories/GHSA-cfh6-pv5c-38jv x_refsource_CONFIRM
Details
- Published
- 2026-08-18
- Last updated
- 2026-08-18
- State
- Published
- Assigner (CNA)
- GitHub_M
Exploit prediction (EPSS)
SSVC assessment (CISA)
- Automatable
- No
- Exploitation
- Proof of concept
- Technical impact
- Partial
Weaknesses (CWE)
- CWE-639Authorization Bypass Through User-Controlled Key
- CWE-862Missing Authorization