Lemur manages TLS certificate creation. Prior to 1.9.2, lemur/certificates/verify.py accepted CRL Distribution Point and OCSP responder URLs from uploaded certificate extensions and used them in crl_verify and ocsp_verify without adequate destination validation. An authenticated operator could submit a certificate through POST /api/1/certificates/upload and cause verify_string to reach loopback, RFC1918, link-local, or instance-metadata destinations such as 169.254.169.254. The requests could probe internal services and create side effects from the Lemur host network position. The CRL path also used an unbounded cache, allowing attacker-controlled entries to persist and consume memory. The fix validates destinations, supports explicit trusted-host allowlists, and bounds the CRL cache. This issue is fixed in version 1.9.2.
Advisories
| Source | ID | Title |
|---|---|---|
Github GHSA |
GHSA-54vg-pfh7-jq95 | Lemur: Crafted CRL/OCSP URLs in uploaded certificates lead to post-authentication SSRF |
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Tue, 18 Aug 2026 21:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Netflix
Netflix lemur |
|
| Vendors & Products |
Netflix
Netflix lemur |
Tue, 18 Aug 2026 19:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | Lemur manages TLS certificate creation. Prior to 1.9.2, lemur/certificates/verify.py accepted CRL Distribution Point and OCSP responder URLs from uploaded certificate extensions and used them in crl_verify and ocsp_verify without adequate destination validation. An authenticated operator could submit a certificate through POST /api/1/certificates/upload and cause verify_string to reach loopback, RFC1918, link-local, or instance-metadata destinations such as 169.254.169.254. The requests could probe internal services and create side effects from the Lemur host network position. The CRL path also used an unbounded cache, allowing attacker-controlled entries to persist and consume memory. The fix validates destinations, supports explicit trusted-host allowlists, and bounds the CRL cache. This issue is fixed in version 1.9.2. | |
| Title | Lemur: Post-authentication SSRF via certificate verification - attacker-controlled CRL and OCSP URLs in uploaded certificates | |
| Weaknesses | CWE-918 | |
| References |
| |
| Metrics |
cvssV3_1
|
Projects
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Status: PUBLISHED
Assigner: GitHub_M
Published:
Updated: 2026-08-18T18:52:25.801Z
Reserved: 2026-06-16T15:13:28.165Z
Link: CVE-2026-55162
No data.
Status : Received
Published: 2026-08-18T19:16:58.217
Modified: 2026-08-18T19:16:58.217
Link: CVE-2026-55162
No data.
OpenCVE Enrichment
Updated: 2026-08-18T20:45:04Z
Weaknesses
Github GHSA