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Fencer Vulns
high 7.3

CVE-2026-71417 json

Lemur: Any user can revoke arbitrary certificates at the CA by uploading a duplicate record and revoking it

published 2026-08-18 2 mo ago modified 2026-10-22 17 d ago also EUVD-2026-61161 , GHSA-pxmc-2ffp-8j67 , PYSEC-2026-3678

cvss
7.3
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.1%
EPSS 0.1% chance of exploitation in 30 days, percentile 1%
public exploits
0
none known

Summary

Lemur manages TLS certificate creation. Prior to 1.9.3, POST /api/1/certificates/upload allowed a non-read-only user to create a duplicate row using another certificate body, authority_id, serial, or external_id without requiring permission on the underlying authority. PUT /api/1/certificates//revoke authorized the caller against only the selected Lemur row, so the creator of the duplicate bypassed CertificatePermission. The duplicate had no cert.endpoints, which also bypassed the safeguard that prevents revocation of deployed certificates. Issuer plugins then revoked the real CA-side certificate using certificate.body or external_id under the stored authority credentials. An attacker could therefore revoke arbitrary managed certificates and cause fleet-wide TLS denial of service. The fix rejects duplicate authority_id and serial identities, requires authority access on upload, and checks every matching row during revocation. This issue is fixed in version 1.9.3.

Patch / fix

  • pypi lemur 1.9.3
  • netflix lemur 1.9.3

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
2 mo ago

Exploit prediction

0.10% chance of exploitation in the next 30 days, higher than 1% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/Netflix/lemur/security/advisories/GHSA-pxmc-2ffp-8j67 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 7.3 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:L/A:H
GitHub 3.1 7.3 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:L/A:H
OSV 3.1 7.3 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:L/A:H

Affected packages

ecosystem package affected fixed in
pypi lemur
<1.9.3
1.9.3

Affected products

  • Netflix lemur

Classification

Weakness
  • CWE-639 Authorization Bypass Through User-Controlled Key

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.