---
id: CVE-2026-55162
title: Lemur manages TLS certificate creation
summary: >-
  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 adequat…
severity: medium
cvss: 6.3
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L'
cwe:
  - CWE-918
vendor: lemur
product: lemur
affected:
  - lemur <= 1.9.1
patched:
  - lemur 1.9.2
published: '2026-08-18'
updated: '2026-09-08'
sourceUpdated: '2026-09-08T21:02:26.047'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-55162'
references:
  - url: >-
      https://github.com/Netflix/lemur/commit/733714a2b00b2f72c3d460e440770e46a3ea9d6a
    label: security-advisories@github.com
  - url: 'https://github.com/Netflix/lemur/releases/tag/v1.9.2'
    label: security-advisories@github.com
  - url: 'https://github.com/Netflix/lemur/security/advisories/GHSA-54vg-pfh7-jq95'
    label: security-advisories@github.com
  - url: 'https://github.com/Netflix/lemur/security/advisories/GHSA-54vg-pfh7-jq95'
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
  - url: 'https://github.com/advisories/GHSA-54vg-pfh7-jq95'
tags:
  - nvd
  - ghsa
  - pip
epss: 0.00216
epssPercentile: 0.10666
ecosystem: pip
ingestedAt: '2026-06-26T16:43:14.207Z'
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Package advisory (CVE-2026-55162)

Affected packages:

- `lemur <= 1.9.1`

Patched in:

- `lemur 1.9.2`

Source: https://github.com/advisories/GHSA-54vg-pfh7-jq95