๐Ÿ” CVE Alert

CVE-2026-55162

MEDIUM 6.3

Lemur: Post-authentication SSRF via certificate verification - attacker-controlled CRL and OCSP URLs in uploaded certificates

CVSS Score
6.3
EPSS Score
0.0%
EPSS Percentile
0th

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.

CWE CWE-918
Vendor netflix
Product lemur
Published Aug 18, 2026
Stay Ahead of the Next One

Get instant alerts for netflix lemur

Be the first to know when new medium vulnerabilities affecting netflix lemur are published โ€” delivered to Slack, Telegram or Discord.

Get Free Alerts โ†’ Free ยท No credit card ยท 60 sec setup

CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L
Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
Low
Availability
Low

Affected Versions

Netflix / lemur
< 1.9.2

References

NVD โ†— CVE.org โ†— EPSS Data โ†—
github.com: https://github.com/Netflix/lemur/security/advisories/GHSA-54vg-pfh7-jq95 github.com: https://github.com/Netflix/lemur/commit/733714a2b00b2f72c3d460e440770e46a3ea9d6a github.com: https://github.com/Netflix/lemur/releases/tag/v1.9.2