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Fencer Vulns
high 7.5

CVE-2026-110353 json

HAProxy 3.2 before 3.4.6 allows a remote unauthenticated attacker to cause a denial of service (worker-thread CPU exhaustion) via a truncat…

published 2026-10-22 18 d ago modified 2026-10-22 17 d ago also EUVD-2026-108001

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.7%
EPSS 0.7% chance of exploitation in 30 days, percentile 54%
public exploits
0
none known

Summary

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.

Patch / fix

  • HAProxy HAProxy 3.2.26, 3.3.17, 3.4.6, 3.5-dev9
  • HAProxy HAProxy Enterprise Edition 3.2r1-378.1259, 3.3r1-377.1005
  • HAProxy Kubernetes Ingress Controller 3.2.17
  • Haproxy Kubernetes Ingress Controller Enterprise 1.11.14-ee11, 3.0.16-ee17, 3.2.17-ee1
  • haproxy Debian 14 3.2.26-1

debian advisories DEBIAN-CVE-2026-110353

  • haproxy Ubuntu 22.04 LTS 2.4.30-0ubuntu0.22.04.3
  • haproxy Ubuntu 24.04 LTS 2.8.30-0ubuntu0.24.04.2
  • haproxy Ubuntu 26.10 3.4.2-1ubuntu4.1
  • haproxy Ubuntu 26.04 LTS 3.2.25-0ubuntu0.26.04.2

ubuntu advisories UBUNTU-CVE-2026-110353

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • haproxy openSUSE Tumbleweed 3.4.7+git57.0faeaeda6-2.1

opensuse advisories openSUSE-SU-2026:12431-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-110353 updated cvss 7.5

haproxy: HAProxy: Denial of Service via truncated HTTP/2 PING frame

  • Red Hat Ceph Storage 5 haproxy, haproxy22
    affected: no fix available “Fix deferred”
  • Red Hat Enterprise Linux 7 haproxy Red Hat Enterprise Linux 8 haproxy Red Hat Enterprise Linux 9 haproxy Red Hat Enterprise Linux 10 haproxy Red Hat OpenShift Container Platform 4 haproxy, haproxy18, haproxy20, haproxy22, haproxy26, haproxy28 Red Hat OpenShift Container Platform 5 haproxy, haproxy32 3.2.22-1.rhocp.el9
    affected: no fix available
  • Red Hat Hardened Images haproxy 3.0.30-0.1.hum1
    fixed: vendor fix RHSA-2026:83844

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
18 d ago

Exploit prediction

0.74% chance of exploitation in the next 30 days, higher than 54% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected products

  • HAProxy HAProxy
  • HAProxy HAProxy Enterprise Edition
  • HAProxy Kubernetes Ingress Controller
  • Haproxy Kubernetes Ingress Controller Enterprise

Classification

Weakness

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.