onyx

onyx --cves cve-2026-27586

CVE-2026-27586

CRITPOCCaddy
score
0.1
cvss
9.1
epss
0.4%
published
2026-02-24
kev added
—
first seen

Caddy < 2.11.1 contains a broken authentication caused by swallowed errors in ClientAuthentication.provision() leading to silent mTLS client certificate authentication failure, letting attackers bypass private CA trust boundary, exploit requires misconfigured or missing CA certificate files.

Timeline

How this CVE moved toward exploitation. Chart: last 30 days — trend score, EPSS, community mentions per day; hover the event lane.

events2026-02-24 — PublishedP2026-10-21 — Tracked by OnyxT2026-10-21 — Public PoCXscore2026-10-21: score 0.10.1epss2026-09-22: epss 0.3%2026-09-23: epss 0.3%2026-09-24: epss 0.4%2026-09-25: epss 0.4%2026-09-26: epss 0.4%2026-09-27: epss 0.4%2026-09-29: epss 0.4%2026-09-30: epss 0.4%2026-10-01: epss 0.4%2026-10-02: epss 0.4%2026-10-03: epss 0.4%2026-10-04: epss 0.4%2026-10-05: epss 0.4%2026-10-06: epss 0.4%2026-10-07: epss 0.4%2026-10-08: epss 0.4%2026-10-09: epss 0.4%2026-10-10: epss 0.4%2026-10-11: epss 0.4%2026-10-12: epss 0.4%2026-10-13: epss 0.4%2026-10-14: epss 0.4%2026-10-15: epss 0.4%2026-10-16: epss 0.4%2026-10-18: epss 0.4%2026-10-19: epss 0.4%2026-10-20: epss 0.4%2026-10-21: epss 0.4%0.4%mentions/day0no mentions in 30 days2026-09-22today
  1. Published
  2. Tracked by Onyx
  3. Public PoC

Exploit availability

Public PoC flagged by vulnx; no direct exploit link among the citations.

Weaknesses

CWE-755

References 3