VulnerabilityDeferred

CVE-2026-55162

The CRL path also used an unbounded cache, allowing attacker-controlled entries to persist and consume memory.

MEDIUM 6.3EPSS 0.20%

Does this matter?

Lower severity and a low EPSS score (0.20%). Track it; it rarely justifies an emergency change on its own.

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.

CVSS 3.1: 6.3 MEDIUMCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L
EPSS: 0.20% probability · 10th percentile
CISA KEV: Not listed
Weakness: CWE-918
Source: security-advisories@github.com

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.