CVE catalog

CVE-2026-110353

haproxy: CVE-2026-110353

Severity: High · CVSS 7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Published: Oct 22, 2026, 2:53:33 AM UTC
Source: [NVD] · [CVE record]
EPSS: 0.74% · Oct 25, 2026

HAProxy 3.2 before 3.4.6 allows a remote unauthenticated attacker to cause a denial of service (worker-thread CPU exhaustion) via a truncated HTTP/2 PING frame. h2c_handle_ping in src/mux_h2.c does not check for a short read, unlike the other H2 frame handlers. Because the incomplete frame cannot be processed, its data is never consumed, and the H2 multiplexer tasklet is repeatedly woken by that pending data without making progress. The CPU spins until timeout http-request closes the connection, and an attacker opening many such connections can sustain high CPU usage.

Vulnerable and fixed packages

Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.

Distribution	Package	Release	Version	Status
Debian	haproxy	sid	`3.2.26-1`	fixed
Debian	haproxy	forky	`3.2.26-1`	fixed
Debian	haproxy	trixie	`3.0.11-1+deb13u3`	vulnerable
Debian	haproxy	trixie-security	`3.0.11-1+deb13u4`	vulnerable
Debian	haproxy	bookworm	`2.6.12-1+deb12u3`	vulnerable
Debian	haproxy	bookworm-security	`2.6.12-1+deb12u4`	vulnerable
Ubuntu	haproxy	pro	`1.7.9-1ubuntu1`	vulnerable
Ubuntu	haproxy	pro	`1.7.9-1ubuntu2`	vulnerable
Ubuntu	haproxy	pro	`1.8.4-1`	vulnerable
Ubuntu	haproxy	pro	`1.8.7-1`	vulnerable
Ubuntu	haproxy	pro	`1.8.8-1`	vulnerable
Ubuntu	haproxy	pro	`1.8.8-1ubuntu0.1`	vulnerable
Ubuntu	haproxy	pro	`1.8.8-1ubuntu0.2`	vulnerable
Ubuntu	haproxy	pro	`1.8.8-1ubuntu0.3`	vulnerable
Ubuntu	haproxy	pro	`1.8.8-1ubuntu0.4`	vulnerable
Ubuntu	haproxy	pro	`1.8.8-1ubuntu0.6`	vulnerable
Ubuntu	haproxy	pro	`1.8.8-1ubuntu0.7`	vulnerable
Ubuntu	haproxy	pro	`1.8.8-1ubuntu0.8`	vulnerable
Ubuntu	haproxy	pro	`1.8.8-1ubuntu0.9`	vulnerable
Ubuntu	haproxy	pro	`1.8.8-1ubuntu0.10`	vulnerable
Ubuntu	haproxy	pro	`1.8.8-1ubuntu0.11`	vulnerable
Ubuntu	haproxy	pro	`1.8.8-1ubuntu0.13`	vulnerable
Ubuntu	haproxy	pro	`1.8.8-1ubuntu0.13+esm2`	vulnerable
Ubuntu	haproxy	pro	`1.8.8-1ubuntu0.13+esm3`	vulnerable
Ubuntu	haproxy	20.04	`2.0.5-1`	vulnerable
Ubuntu	haproxy	20.04	`2.0.8-1`	vulnerable
Ubuntu	haproxy	20.04	`2.0.9-1`	vulnerable
Ubuntu	haproxy	20.04	`2.0.10-1`	vulnerable
Ubuntu	haproxy	20.04	`2.0.10-1ubuntu1`	vulnerable
Ubuntu	haproxy	20.04	`2.0.11-1ubuntu1`	vulnerable
Ubuntu	haproxy	20.04	`2.0.12-1ubuntu2`	vulnerable
Ubuntu	haproxy	20.04	`2.0.13-1ubuntu2`	vulnerable
Ubuntu	haproxy	20.04	`2.0.13-2`	vulnerable
Ubuntu	haproxy	20.04	`2.0.13-2ubuntu0.1`	vulnerable
Ubuntu	haproxy	20.04	`2.0.13-2ubuntu0.2`	vulnerable
Ubuntu	haproxy	20.04	`2.0.13-2ubuntu0.3`	vulnerable
Ubuntu	haproxy	20.04	`2.0.13-2ubuntu0.5`	vulnerable
Ubuntu	haproxy	20.04	`2.0.29-0ubuntu1`	vulnerable
Ubuntu	haproxy	20.04	`2.0.29-0ubuntu1.1`	vulnerable
Ubuntu	haproxy	20.04	`2.0.29-0ubuntu1.3`	vulnerable
Ubuntu	haproxy	20.04	`2.0.31-0ubuntu0.1`	vulnerable
Ubuntu	haproxy	20.04	`2.0.31-0ubuntu0.2`	vulnerable
Ubuntu	haproxy	20.04	`2.0.31-0ubuntu0.3`	vulnerable
Ubuntu	haproxy	20.04	`2.0.33-0ubuntu0.1`	vulnerable
Ubuntu	haproxy	22.04	`2.2.9-2ubuntu2`	vulnerable
Ubuntu	haproxy	22.04	`2.4.8-1`	vulnerable
Ubuntu	haproxy	22.04	`2.4.8-2ubuntu3`	vulnerable
Ubuntu	haproxy	22.04	`2.4.11-1ubuntu1`	vulnerable
Ubuntu	haproxy	22.04	`2.4.12-1ubuntu1`	vulnerable
Ubuntu	haproxy	22.04	`2.4.12-1ubuntu2`	vulnerable
Ubuntu	haproxy	22.04	`2.4.13-1ubuntu1`	vulnerable
Ubuntu	haproxy	22.04	`2.4.14-1ubuntu1`	vulnerable
Ubuntu	haproxy	22.04	`2.4.18-0ubuntu1`	vulnerable
Ubuntu	haproxy	22.04	`2.4.18-0ubuntu1.1`	vulnerable
Ubuntu	haproxy	22.04	`2.4.18-0ubuntu1.2`	vulnerable
Ubuntu	haproxy	22.04	`2.4.18-0ubuntu1.3`	vulnerable
Ubuntu	haproxy	22.04	`2.4.22-0ubuntu0.22.04.1`	vulnerable
Ubuntu	haproxy	22.04	`2.4.22-0ubuntu0.22.04.2`	vulnerable
Ubuntu	haproxy	22.04	`2.4.22-0ubuntu0.22.04.3`	vulnerable
Ubuntu	haproxy	22.04	`2.4.24-0ubuntu0.22.04.1`	vulnerable
Ubuntu	haproxy	22.04	`2.4.24-0ubuntu0.22.04.2`	vulnerable
Ubuntu	haproxy	22.04	`2.4.24-0ubuntu0.22.04.3`	vulnerable
Ubuntu	haproxy	22.04	`2.4.29-0ubuntu0.22.04.1`	vulnerable
Ubuntu	haproxy	22.04	`2.4.30-0ubuntu0.22.04.1`	vulnerable
Ubuntu	haproxy	22.04	`2.4.30-0ubuntu0.22.04.2`	vulnerable
Ubuntu	haproxy	24.04	`2.6.15-1ubuntu2`	vulnerable
Ubuntu	haproxy	24.04	`2.8.5-1ubuntu1`	vulnerable
Ubuntu	haproxy	24.04	`2.8.5-1ubuntu2`	vulnerable
Ubuntu	haproxy	24.04	`2.8.5-1ubuntu3`	vulnerable
Ubuntu	haproxy	24.04	`2.8.5-1ubuntu3.1`	vulnerable
Ubuntu	haproxy	24.04	`2.8.5-1ubuntu3.2`	vulnerable
Ubuntu	haproxy	24.04	`2.8.5-1ubuntu3.3`	vulnerable
Ubuntu	haproxy	24.04	`2.8.5-1ubuntu3.4`	vulnerable
Ubuntu	haproxy	24.04	`2.8.15-0ubuntu0.24.04.1`	vulnerable
Ubuntu	haproxy	24.04	`2.8.16-0ubuntu0.24.04.1`	vulnerable
Ubuntu	haproxy	24.04	`2.8.16-0ubuntu0.24.04.2`	vulnerable
Ubuntu	haproxy	24.04	`2.8.16-0ubuntu0.24.04.3`	vulnerable
Ubuntu	haproxy	24.04	`2.8.30-0ubuntu0.24.04.1`	vulnerable
Ubuntu	haproxy	26.10	`3.2.9-1ubuntu2`	vulnerable
Ubuntu	haproxy	26.10	`3.2.9-1ubuntu2.1`	vulnerable
Ubuntu	haproxy	26.10	`3.2.9-1ubuntu3`	vulnerable
Ubuntu	haproxy	26.10	`3.4.2-1ubuntu2`	vulnerable
Ubuntu	haproxy	26.10	`3.4.2-1ubuntu3`	vulnerable
Ubuntu	haproxy	26.10	`3.4.2-1ubuntu4`	vulnerable
Ubuntu	haproxy	26.04	`3.0.10-1ubuntu3`	vulnerable
Ubuntu	haproxy	26.04	`3.2.9-1ubuntu1`	vulnerable
Ubuntu	haproxy	26.04	`3.2.9-1ubuntu2`	vulnerable
Ubuntu	haproxy	26.04	`3.2.9-1ubuntu2.1`	vulnerable
Ubuntu	haproxy	26.04	`3.2.9-1ubuntu2.2`	vulnerable
Ubuntu	haproxy	26.04	`3.2.25-0ubuntu0.26.04.1`	vulnerable

Fixed-version evidence

Distribution	Package	Type	Release	Fixed version	Urgency	Origin	Bugs
Debian	haproxy	source	sid	`3.2.26-1`	not yet assigned	Not reported	Not reported
Debian	haproxy	source	forky	`3.2.26-1`	not yet assigned	Not reported	Not reported
Debian	haproxy	source	trixie	`(unfixed)`	not yet assigned	Not reported	Not reported
Debian	haproxy	source	bookworm	`(unfixed)`	not yet assigned	Not reported	Not reported

Notes

[trixie] haproxy: Minor issue

OpenFactory catalog packages

[Debian 12 (Bookworm)]

[haproxy]Affected
Details (4)
- 2.6.12-1+deb12u3 · amd64 · bookworm
  Affected
  dsa · haproxy · debian · bookworm; dsa · haproxy · debian · 12
- 2.6.12-1+deb12u3 · arm64 · bookworm
  Affected
  dsa · haproxy · debian · bookworm; dsa · haproxy · debian · 12
- 2.6.12-1+deb12u3 · amd64 · bookworm-security
  Affected
  dsa · haproxy · debian · bookworm; dsa · haproxy · debian · 12
- 2.6.12-1+deb12u3 · arm64 · bookworm-security
  Affected
  dsa · haproxy · debian · bookworm; dsa · haproxy · debian · 12
[haproxy-doc]Affected
Source package: [haproxy]
Details (4)
- 2.6.12-1+deb12u3 · all · bookworm
  Affected
  dsa · haproxy · debian · bookworm; dsa · haproxy · debian · 12
- 2.6.12-1+deb12u3 · all · bookworm
  Affected
  dsa · haproxy · debian · bookworm; dsa · haproxy · debian · 12
- 2.6.12-1+deb12u3 · all · bookworm-security
  Affected
  dsa · haproxy · debian · bookworm; dsa · haproxy · debian · 12
- 2.6.12-1+deb12u3 · all · bookworm-security
  Affected
  dsa · haproxy · debian · bookworm; dsa · haproxy · debian · 12
[vim-haproxy]Affected
Source package: [haproxy]
Details (4)
- 2.6.12-1+deb12u3 · all · bookworm
  Affected
  dsa · haproxy · debian · bookworm; dsa · haproxy · debian · 12
- 2.6.12-1+deb12u3 · all · bookworm
  Affected
  dsa · haproxy · debian · bookworm; dsa · haproxy · debian · 12
- 2.6.12-1+deb12u3 · all · bookworm-security
  Affected
  dsa · haproxy · debian · bookworm; dsa · haproxy · debian · 12
- 2.6.12-1+deb12u3 · all · bookworm-security
  Affected
  dsa · haproxy · debian · bookworm; dsa · haproxy · debian · 12

[Debian 13 (Trixie)]

[haproxy]Affected
Details (5)
- 3.0.11-1+deb13u3 · amd64 · trixie
  Affected
  dsa · haproxy · debian · 13
- 3.0.11-1+deb13u3 · arm64 · trixie
  Affected
  dsa · haproxy · debian · 13
- 3.0.11-1+deb13u3 · amd64 · trixie-security · Historical version
  Affected
  dsa · haproxy · debian · 13
- 3.0.11-1+deb13u3 · arm64 · trixie-security
  Affected
  dsa · haproxy · debian · 13
- 3.0.11-1+deb13u4 · amd64 · trixie-security
  Affected
  dsa · haproxy · debian · 13
[haproxy-doc]Affected
Source package: [haproxy]
Details (5)
- 3.0.11-1+deb13u3 · all · trixie
  Affected
  dsa · haproxy · debian · 13
- 3.0.11-1+deb13u3 · all · trixie
  Affected
  dsa · haproxy · debian · 13
- 3.0.11-1+deb13u3 · all · trixie-security
  Affected
  dsa · haproxy · debian · 13
- 3.0.11-1+deb13u3 · all · trixie-security · Historical version
  Affected
  dsa · haproxy · debian · 13
- 3.0.11-1+deb13u4 · all · trixie-security
  Affected
  dsa · haproxy · debian · 13
[vim-haproxy]Affected
Source package: [haproxy]
Details (5)
- 3.0.11-1+deb13u3 · all · trixie
  Affected
  dsa · haproxy · debian · 13
- 3.0.11-1+deb13u3 · all · trixie
  Affected
  dsa · haproxy · debian · 13
- 3.0.11-1+deb13u3 · all · trixie-security · Historical version
  Affected
  dsa · haproxy · debian · 13
- 3.0.11-1+deb13u3 · all · trixie-security
  Affected
  dsa · haproxy · debian · 13
- 3.0.11-1+deb13u4 · all · trixie-security
  Affected
  dsa · haproxy · debian · 13

Observed: Oct 27, 2026, 4:07:55 AM UTC

References

[Debian Security Tracker] · [FIRST EPSS] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX]