CVE-2026-110353
HAProxy 3.2 before 3.4.6 allows a remote unauthenticated attacker to cause a denial of service ...
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
7.5
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.
- Record
CVE-2026-110353- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-252
- Updated
- 2026-11-02
EUVDEUVD-2026-108001
7.5
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.
- Record
EUVD-2026-108001- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-p9cc-qc4f-7x35
7.5
HAProxy 3.2 before 3.4.6 allows a remote unauthenticated attacker to cause a denial of service ...
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.
- Record
GHSA-p9cc-qc4f-7x35- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-252
- Updated
- 2026-11-02
NVD
7.5
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.
- Record
CVE-2026-110353- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-252
- Updated
- 2026-11-02
OSV
7.5
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.
- Record
CVE-2026-110353- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-252
- Updated
- 2026-11-06
OSVDEBIAN-CVE-2026-110353
7.5
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.
- Record
DEBIAN-CVE-2026-110353- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVUBUNTU-CVE-2026-110353
7.5
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.
- Record
UBUNTU-CVE-2026-110353- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-03
OSVopenSUSE-SU-2026:12431-1 No score
haproxy-3.4.7+git57.0faeaeda6-2.1 on GA media
These are all security issues fixed in the haproxy-3.4.7+git57.0faeaeda6-2.1 package on the GA media of openSUSE Tumbleweed.
- Record
openSUSE-SU-2026:12431-1- Updated
- 2026-11-06
OSVUSN-8972-1 No score
haproxy vulnerabilities
It was discovered that HAProxy incorrectly handled truncated HTTP/2 PING frames. A remote attacker could possibly use this issue to cause HAProxy to consume excessive CPU resources, leading to a denial of service. (CVE-2026-110353)
It was discovered that HAProxy incorrectly handled certain HTTP/1.1 chunked requests. A remote attacker could possibly use this issue to cause HAProxy to consume excessive CPU resources, leading to a denial of service. (CVE-2026-110354)
- Record
USN-8972-1- Updated
- 2026-11-04
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
haproxyDebian:12 |
All versions, plus listed versions 2.6.12-12.6.12-1+deb12u12.6.12-1+deb12u22.6.12-1+deb12u32.6.12-1+deb12u4 Show 45 moreShow less2.6.13-12.6.14-12.6.15-12.7.0-12.7.1-12.7.2-12.7.2-22.7.3-12.7.4-12.7.5-12.7.6-12.7.7-12.7.8-12.8.0-12.8.1-12.8.2-12.8.3-12.8.4-12.8.4-22.8.5-12.9.0-12.9.1-12.9.10-12.9.11-12.9.12-12.9.2-12.9.3-12.9.4-12.9.5-12.9.6-12.9.7-12.9.8-12.9.9-13.0.0-13.0.1-13.0.10-13.0.11-13.0.2-13.0.3-13.0.4-13.0.5-13.0.6-13.0.6-23.0.6-33.0.7-1 |
None known |
haproxyDebian:13 |
All versions, plus listed versions 3.0.11-13.0.11-1+deb13u13.0.11-1+deb13u23.0.11-1+deb13u33.0.11-1+deb13u4 Show 45 moreShow less3.1.0-13.1.0-23.1.1-13.1.2-13.1.3-13.1.5-13.1.6-13.1.7-13.2.0-13.2.1-13.2.10-13.2.11-13.2.11-23.2.12-13.2.13-13.2.14-13.2.15-13.2.16-13.2.17-13.2.18-13.2.19-13.2.20-13.2.21-13.2.22-13.2.23-13.2.24-13.2.25-13.2.26-13.2.3-13.2.3-23.2.4-13.2.5-13.2.5-23.2.6-13.2.7-13.2.8-13.2.9-13.3.0-13.3.1-13.3.10-13.3.2-13.3.2-23.3.3-13.3.4-13.3.5-1 |
None known |
haproxyDebian:14 |
before 3.2.26-1, plus listed versions 3.0.11-13.1.0-13.1.0-23.1.1-13.1.2-1 Show 32 moreShow less3.1.3-13.1.5-13.1.6-13.1.7-13.2.0-13.2.1-13.2.10-13.2.11-13.2.11-23.2.12-13.2.13-13.2.14-13.2.15-13.2.16-13.2.17-13.2.18-13.2.19-13.2.20-13.2.21-13.2.22-13.2.23-13.2.24-13.2.25-13.2.3-13.2.3-23.2.4-13.2.5-13.2.5-23.2.6-13.2.7-13.2.8-13.2.9-1 |
3.2.26-1 |
haproxyUbuntu:Pro:16.04:LTS |
All versions, plus listed versions 1.5.14-11.5.15-11.6.2-11.6.2-21.6.2-2ubuntu1 Show 7 moreShow less1.6.2-2ubuntu31.6.3-11.6.3-1ubuntu0.11.6.3-1ubuntu0.21.6.3-1ubuntu0.31.6.3-1ubuntu0.3+esm11.6.3-1ubuntu0.3+esm2 |
None known |
haproxyUbuntu:Pro:18.04:LTS |
All versions, plus listed versions 1.7.9-1ubuntu11.7.9-1ubuntu21.8.4-11.8.7-11.8.8-1 Show 13 moreShow less1.8.8-1ubuntu0.11.8.8-1ubuntu0.21.8.8-1ubuntu0.31.8.8-1ubuntu0.41.8.8-1ubuntu0.61.8.8-1ubuntu0.71.8.8-1ubuntu0.81.8.8-1ubuntu0.91.8.8-1ubuntu0.101.8.8-1ubuntu0.111.8.8-1ubuntu0.131.8.8-1ubuntu0.13+esm21.8.8-1ubuntu0.13+esm3 |
None known |
haproxyUbuntu:20.04:LTS |
All versions, plus listed versions 2.0.5-12.0.8-12.0.9-12.0.10-12.0.10-1ubuntu1 Show 15 moreShow less2.0.11-1ubuntu12.0.12-1ubuntu22.0.13-1ubuntu22.0.13-22.0.13-2ubuntu0.12.0.13-2ubuntu0.22.0.13-2ubuntu0.32.0.13-2ubuntu0.52.0.29-0ubuntu12.0.29-0ubuntu1.12.0.29-0ubuntu1.32.0.31-0ubuntu0.12.0.31-0ubuntu0.22.0.31-0ubuntu0.32.0.33-0ubuntu0.1 |
None known |
haproxyUbuntu:22.04:LTS |
before 2.4.30-0ubuntu0.22.04.3, plus listed versions 2.2.9-2ubuntu22.4.8-12.4.8-2ubuntu32.4.11-1ubuntu12.4.12-1ubuntu1 Show 16 moreShow less2.4.12-1ubuntu22.4.13-1ubuntu12.4.14-1ubuntu12.4.18-0ubuntu12.4.18-0ubuntu1.12.4.18-0ubuntu1.22.4.18-0ubuntu1.32.4.22-0ubuntu0.22.04.12.4.22-0ubuntu0.22.04.22.4.22-0ubuntu0.22.04.32.4.24-0ubuntu0.22.04.12.4.24-0ubuntu0.22.04.22.4.24-0ubuntu0.22.04.32.4.29-0ubuntu0.22.04.12.4.30-0ubuntu0.22.04.12.4.30-0ubuntu0.22.04.2 |
2.4.30-0ubuntu0.22.04.3 |
haproxyUbuntu:24.04:LTS |
before 2.8.30-0ubuntu0.24.04.2, plus listed versions 2.6.15-1ubuntu22.8.5-1ubuntu12.8.5-1ubuntu22.8.5-1ubuntu32.8.5-1ubuntu3.1 Show 8 moreShow less2.8.5-1ubuntu3.22.8.5-1ubuntu3.32.8.5-1ubuntu3.42.8.15-0ubuntu0.24.04.12.8.16-0ubuntu0.24.04.12.8.16-0ubuntu0.24.04.22.8.16-0ubuntu0.24.04.32.8.30-0ubuntu0.24.04.1 |
2.8.30-0ubuntu0.24.04.2 |
haproxyUbuntu:26.10 |
before 3.4.2-1ubuntu4.1, plus listed versions 3.2.9-1ubuntu23.2.9-1ubuntu2.13.2.9-1ubuntu33.4.2-1ubuntu23.4.2-1ubuntu33.4.2-1ubuntu4 |
3.4.2-1ubuntu4.1 |
haproxyUbuntu:26.04:LTS |
before 3.2.25-0ubuntu0.26.04.2, plus listed versions 3.0.10-1ubuntu33.2.9-1ubuntu13.2.9-1ubuntu23.2.9-1ubuntu2.13.2.9-1ubuntu2.23.2.25-0ubuntu0.26.04.1 |
3.2.25-0ubuntu0.26.04.2 |
Show 5 moreShow less
| Package | Affected | Fixed |
|---|---|---|
haproxyUbuntu:22.04:LTS From an advisory covering 2 CVEs |
before 2.4.30-0ubuntu0.22.04.3, plus listed versions 2.2.9-2ubuntu22.4.8-12.4.8-2ubuntu32.4.11-1ubuntu12.4.12-1ubuntu1 Show 16 moreShow less2.4.12-1ubuntu22.4.13-1ubuntu12.4.14-1ubuntu12.4.18-0ubuntu12.4.18-0ubuntu1.12.4.18-0ubuntu1.22.4.18-0ubuntu1.32.4.22-0ubuntu0.22.04.12.4.22-0ubuntu0.22.04.22.4.22-0ubuntu0.22.04.32.4.24-0ubuntu0.22.04.12.4.24-0ubuntu0.22.04.22.4.24-0ubuntu0.22.04.32.4.29-0ubuntu0.22.04.12.4.30-0ubuntu0.22.04.12.4.30-0ubuntu0.22.04.2 |
2.4.30-0ubuntu0.22.04.3 |
haproxyUbuntu:24.04:LTS From an advisory covering 2 CVEs |
before 2.8.30-0ubuntu0.24.04.2, plus listed versions 2.6.15-1ubuntu22.8.5-1ubuntu12.8.5-1ubuntu22.8.5-1ubuntu32.8.5-1ubuntu3.1 Show 8 moreShow less2.8.5-1ubuntu3.22.8.5-1ubuntu3.32.8.5-1ubuntu3.42.8.15-0ubuntu0.24.04.12.8.16-0ubuntu0.24.04.12.8.16-0ubuntu0.24.04.22.8.16-0ubuntu0.24.04.32.8.30-0ubuntu0.24.04.1 |
2.8.30-0ubuntu0.24.04.2 |
haproxyUbuntu:26.10 From an advisory covering 2 CVEs |
before 3.4.2-1ubuntu4.1, plus listed versions 3.2.9-1ubuntu23.2.9-1ubuntu2.13.2.9-1ubuntu33.4.2-1ubuntu23.4.2-1ubuntu33.4.2-1ubuntu4 |
3.4.2-1ubuntu4.1 |
haproxyUbuntu:26.04:LTS From an advisory covering 2 CVEs |
before 3.2.25-0ubuntu0.26.04.2, plus listed versions 3.0.10-1ubuntu33.2.9-1ubuntu13.2.9-1ubuntu23.2.9-1ubuntu2.13.2.9-1ubuntu2.23.2.25-0ubuntu0.26.04.1 |
3.2.25-0ubuntu0.26.04.2 |
haproxyopenSUSE:Tumbleweed From an advisory covering 2 CVEs |
before 3.4.7+git57.0faeaeda6-2.1 | 3.4.7+git57.0faeaeda6-2.1 |
History
| Recorded | Changed | Sources |
|---|---|---|
| affected, aliases, references | OSV | |
| affected | ||
| affected, aliases, references | OSV | |
| affected, facts, references | OSV | |
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-110353 is a high vulnerability (CVSS 7.5) in Haproxy, published October 22, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.74%, the 54th percentile. Fixed in haproxy 3.2.26-1.
References
git.haproxy.org?p=haproxy.git;a=commit;h=cec63e95f62a7412484f1134f5aa227e5b7e1466
nvd.nist.gov/vuln/detail/CVE-2026-110353
github.com/advisories/GHSA-p9cc-qc4f-7x35
git.haproxy.org/git/haproxy.git
github.com/CVEProject/cvelistV5/tree/main/cves/2026/110xxx/CVE-2026-110353.json
security-tracker.debian.org/tracker/CVE-2026-110353
Left out here: 69 versions. The JSON record has them.