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TI-2026-79140 Aliases CVE-2026-110353GHSA-p9cc-qc4f-7x35

Denial of service in HAProxy via truncated HTTP/2 PING frame

Priority MEDIUM 40CWE-252Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
None · None · High
Fix status
Partial Red Hat: 1 fixed, 7 without a fix

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.

Summary

HAProxy from 3.2.0 before 3.2.26, from 3.3.0 before 3.3.17, from 3.4.0 before 3.4.6 and from 3.5-dev before 3.5-dev9 is affected. The h2c_handle_ping function does not check for a short read (CWE-252), so the HTTP/2 multiplexer keeps waking up on unconsumed data without making progress. A remote unauthenticated attacker can exhaust worker-thread CPU and cause a denial of service by opening many connections that send a truncated HTTP/2 PING frame.

Written with Claude Haiku 5.5 from the sources below · 2026-10-30

Description from the CNA

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00738 54th percentileScored 2026-11-07
Fix Partial HAProxy (HAProxy): 3.2.26, 3.3.17, 3.4.6 +1HAProxy Enterprise Edition (HAProxy): 3.2r1-378.1259, 3.3r1-377.1005+2 more productsRed Hat: 1 advisoryRed Hat: 1 fixed, 7 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
HAProxyHAProxy3.2.0 to before 3.2.26; 3.3.0 to before 3.3.17; 3.4.0 to before 3.4.6; 3.5-dev to before 3.5-dev93.2.26, 3.3.17, 3.4.6, 3.5-dev9Patch availableCNA
HAProxyHAProxy Enterprise Edition3.2.0r1 to before 3.2r1-378.1259; 3.3.0r1 to before 3.3r1-377.10053.2r1-378.1259, 3.3r1-377.1005Patch availableCNA
HAProxyKubernetes Ingress Controller3.2.0 to before 3.2.173.2.17Patch availableCNA
HAProxyKubernetes Ingress Controller Enterprise3.2.0 to before 3.2.17-ee1; 3.0 to before 3.0.16-ee17; 1.11 to before 1.11.14-ee113.2.17-ee1, 3.0.16-ee17, 1.11.14-ee11Patch availableCNA
  • HAProxy VendorHAProxy Affected 3.2.0 to before 3.2.26; 3.3.0 to before 3.3.17; 3.4.0 to before 3.4.6; 3.5-dev to before 3.5-dev9 Fixed in 3.2.26, 3.3.17, 3.4.6, 3.5-dev9 Patch available CNA
  • HAProxy Enterprise Edition VendorHAProxy Affected 3.2.0r1 to before 3.2r1-378.1259; 3.3.0r1 to before 3.3r1-377.1005 Fixed in 3.2r1-378.1259, 3.3r1-377.1005 Patch available CNA
  • Kubernetes Ingress Controller VendorHAProxy Affected 3.2.0 to before 3.2.17 Fixed in 3.2.17 Patch available CNA
  • Kubernetes Ingress Controller Enterprise VendorHAProxy Affected 3.2.0 to before 3.2.17-ee1; 3.0 to before 3.0.16-ee17; 1.11 to before 1.11.14-ee11 Fixed in 3.2.17-ee1, 3.0.16-ee17, 1.11.14-ee11 Patch available CNA

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPEVersionsRoleVendor
cpe:2.3:a:haproxy:haproxy:*:*:*:*:*:*:*:*——HAProxy
  • cpe:2.3:a:haproxy:haproxy:*:*:*:*:*:*:*:* Versions — — ·HAProxy

Remediation

Upgrade HAProxy to 3.2.26, 3.3.17, 3.4.6 or 3.5-dev9, and HAProxy Enterprise Edition to 3.2r1-378.1259 or 3.3r1-377.1005. Kubernetes Ingress Controller is fixed in 3.2.17, and Kubernetes Ingress Controller Enterprise in 3.2.17-ee1, 3.0.16-ee17 or 1.11.14-ee11. Red Hat fixes Red Hat Hardened Images in RHSA-2026:83844. The sources list no fixed version for Red Hat Enterprise Linux 7, 8, 9 and 10, Red Hat Ceph Storage 5 and Red Hat OpenShift Container Platform 4 and 5.

Written with Claude Haiku 5.5 from the sources below · 2026-10-30

  • Fix · CNA HAProxy (HAProxy) Fixed in 3.2.26, 3.3.17, 3.4.6, 3.5-dev9
  • Fix · CNA HAProxy Enterprise Edition (HAProxy) Fixed in 3.2r1-378.1259, 3.3r1-377.1005
  • Fix · CNA Kubernetes Ingress Controller (HAProxy) Fixed in 3.2.17
  • Fix · CNA Kubernetes Ingress Controller Enterprise (Haproxy) Fixed in 3.2.17-ee1, 3.0.16-ee17, 1.11.14-ee11

Red Hat 1 advisory

  • RHSA-2026:83844 Released 2026-10-16 · Red Hat rating Important
    Red Hat Hardened Images RPMs bug fix and enhancement update
    • Red Hat Hardened Images haproxy-3.0.30-0.1.hum1@aarch64, haproxy-3.0.30-0.1.hum1@s390x, haproxy-3.0.30-0.1.hum1@src +1

Vendor assessments

Red Hat

Red Hat rating: Important. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Ceph Storage 5AffectedNo fix yet: Fix deferred
Red Hat Enterprise Linux 10AffectedNo fix yet
Red Hat Enterprise Linux 7AffectedNo fix yet
Red Hat Enterprise Linux 8AffectedNo fix yet
Red Hat Enterprise Linux 9AffectedNo fix yet
Red Hat OpenShift Container Platform 4AffectedNo fix yet
Red Hat OpenShift Container Platform 5AffectedNo fix yet
Red Hat Hardened ImagesFixed RHSA-2026:83844

Timeline

  1. 2026-10-22 Threatist record created from CVE-2026-110353
  2. 2026-10-22 Alias added: GHSA-p9cc-qc4f-7x35
  3. 2026-10-22 CISA SSVC decision points changed
  4. 2026-10-22 Priority changed: MEDIUM → LOW
  5. 2026-10-23 Fix available: RHSA-2026:83844 · Red Hat
  6. 2026-10-23 Fix available: Red Hat Hardened Images · Red Hat
  7. 2026-10-23 CVSS score added · Red Hat
  8. 2026-10-23 Priority changed: LOW → MEDIUM
  9. 2026-10-30 Affected versions changed · Red Hat

References

Advisory 1

  • TI-2020-08973 In hpack_dht_insert in hpack-tbl.c in the HPACK decoder in HAProxy 1.8 through 2.x before… CVSS 3.1HIGH 8.8
  • TI-2023-21094 HAProxy through 2.0.32, 2.1.x and 2.2.x through 2.2.30, 2.3.x and 2.4.x through 2.4.23… CVSS 3.1HIGH 7.2
  • TI-2019-10602 HAProxy through 2.0.2 allows attackers to cause a denial of service (ha_panic) via… CVSS 3.0HIGH 7.5
  • TI-2021-17418 An integer overflow exists in HAProxy 2.0 through 2.5 in htx_add_header that can be… CVSS 3.1HIGH 7.5
  • TI-2016-04651 HAproxy 1.6.x before 1.6.6, when a deny comes from a reqdeny rule, allows remote… CVSS 3.0HIGH 7.5
  • TI-2026-25946 An issue was discovered in HAProxy before 3.3.6. CVSS 3.1MEDIUM 5.8
See all 42 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences