CVE-2026-110353
Publication date 22 October 2026
Last updated 3 November 2026
Ubuntu priority
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.
Status
| Package | Ubuntu Release | Status |
|---|---|---|
| haproxy | 26.10 stonking |
Fixed in 3.4.2-1ubuntu4.1
|
| 26.04 LTS resolute |
Fixed in 3.2.25-0ubuntu0.26.04.2
|
|
| 24.04 LTS noble |
Fixed in 2.8.30-0ubuntu0.24.04.2
|
|
| 22.04 LTS jammy |
Fixed in 2.4.30-0ubuntu0.22.04.3
|
|
| 20.04 LTS focal |
Needs evaluation
|
|
| 18.04 LTS bionic |
Needs evaluation
|
|
| 16.04 LTS xenial |
Needs evaluation
|
Patch details
Severity score breakdown
CVSS version: CVSS v3.0
Base score
7.5 · High
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
References
Related Ubuntu Security Notices (USN)
- USN-8972-1
- HAProxy vulnerabilities
- 3 November 2026