All vulnerabilities
CVE-2026-110353

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 no

HAProxy HAProxy
Open in ThreatlineRecord JSON
CVSS
7.5High
ExploitationNo known exploitationNot in CISA KEV, which does not prove it is unexploitedCISA KEV
Exploit odds (EPSS)0.68%Chance of exploitation activity in the next 30 days, higher than 52% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed in3.2.26Also 3.3.17, 3.4.6 and 7 moreCVE List
Published22 Oct 2026Updated 22 Oct 2026CVE List

What fixes it

Show all 10 fixed versions
  • 3.2.17Kubernetes Ingress ControllerCVE List
  • 3.2.17-ee1Kubernetes Ingress Controller EnterpriseCVE List
  • 3.0.16-ee17Kubernetes Ingress Controller EnterpriseCVE List
  • 1.11.14-ee11Kubernetes Ingress Controller EnterpriseCVE List

A fixed version on one release line is not the upgrade target for every line. Check your exact version and any vendor backports.

Description

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.

Text from CVE List

Affected versions 10

  • HAProxyaffected: 3.2.0 before 3.2.26CVE List
  • HAProxyaffected: 3.3.0 before 3.3.17CVE List
  • HAProxyaffected: 3.4.0 before 3.4.6CVE List
  • HAProxyaffected: 3.5-dev before 3.5-dev9CVE List
  • HAProxy Enterprise Editionaffected: 3.2.0r1 before 3.2r1-378.1259CVE List
  • HAProxy Enterprise Editionaffected: 3.3.0r1 before 3.3r1-377.1005CVE List
  • Kubernetes Ingress Controlleraffected: 3.2.0 before 3.2.17CVE List
  • Kubernetes Ingress Controller Enterpriseaffected: 3.2.0 before 3.2.17-ee1CVE List
  • Kubernetes Ingress Controller Enterpriseaffected: 3.0 before 3.0.16-ee17CVE List
  • Kubernetes Ingress Controller Enterpriseaffected: 1.11 before 1.11.14-ee11CVE List

References 1