CVE-2026-55162Network attack vector

Authenticated SSRF via certificate revocation URLs

Published Aug 18, 2026 · Updated Aug 19, 2026

Server-side request forgery in Netflix Lemur before 1.9.2 allows remote authenticated users to reach internal hosts via crafted certificate uploads. In lemur/certificates/verify.py, crl_verify passes the certificate's CRL Distribution Point URL to requests.get, and ocsp_verify passes the certificate's OCSP responder URL to openssl ocsp, without validating destination classes or enforcing a trusted-host allowlist. Reachability requires an authenticated operator role on POST /api/1/certificates/upload; successful exploitation can probe loopback, RFC1918, link-local, or instance-metadata services from the Lemur host, and the CRL path can also retain attacker-controlled cache entries.

CVSS severity6.3
Medium
EPSS probability0.20%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Server-side request forgery in Netflix Lemur before 1.9.2 allows remote authenticated users to reach internal hosts via crafted certificate uploads. In lemur/certificates/verify.py, crl_verify passes the certificate's CRL Distribution Point URL to requests.get, and ocsp_verify passes the certificate's OCSP responder URL to openssl ocsp, without validating destination classes or enforcing a trusted-host allowlist. Reachability requires an authenticated operator role on POST /api/1/certificates/upload; successful exploitation can probe loopback, RFC1918, link-local, or instance-metadata services from the Lemur host, and the CRL path can also retain attacker-controlled cache entries.

The record

CVE
CVE-2026-55162
Published
Aug 18, 2026
Updated
Aug 19, 2026
Vendor
Netflix
Product
Lemur
Classifications
CWE-918, T1046, T1190
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 18, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 19, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 1.9.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Netflix · Lemurversion=< 1.9.2

Published CVSS scores

6.3GitHub Advisory DatabaseCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-918Server-Side Request Forgery (SSRF)
T1046Network Service Discovery
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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