onyx

onyx --cves cve-2026-55203

CVE-2026-55203

HIGHHAProxy
score
<0.1
cvss
7.5
epss
0.3%
published
2026-06-18
kev added
—
first seen

HAProxy through 3.4.0 contains an integer overflow caused by improper handling of the drl field in the fcgi_conn structure, letting malicious FastCGI backends desynchronize the FCGI framing parser, exploit requires malicious backend.

Timeline

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

events2026-06-18 — PublishedP2026-10-21 (seen by) — Tracked by OnyxTscore2026-10-21: score <0.1<0.1epss2026-09-22: epss 0.3%2026-09-23: epss 0.3%2026-09-24: epss 0.6%2026-09-25: epss 0.6%2026-09-26: epss 0.6%2026-09-27: epss 0.6%2026-09-29: epss 0.6%2026-09-30: epss 0.6%2026-10-01: epss 0.6%2026-10-02: epss 0.6%2026-10-03: epss 0.6%2026-10-04: epss 0.6%2026-10-05: epss 0.6%2026-10-06: epss 0.6%2026-10-07: epss 0.6%2026-10-08: epss 0.6%2026-10-09: epss 0.3%2026-10-10: epss 0.3%2026-10-11: epss 0.3%2026-10-12: epss 0.3%2026-10-13: epss 0.3%2026-10-14: epss 0.3%2026-10-15: epss 0.3%2026-10-16: epss 0.3%2026-10-18: epss 0.3%2026-10-19: epss 0.3%2026-10-20: epss 0.3%2026-10-21: epss 0.3%0.3%mentions/day0no mentions in 30 days2026-09-22today
  1. Published
  2. Tracked by Onyx

Weaknesses

CWE-190

References 2