CVE-2026-110353

haproxy: HAProxy 3.2 before 3.4.6 allows a remote unauthenticated attacker to cause a denial of service (worker-thread CPU exh...

CVE-2026-110353 is fixed in 2 products on 1 platform, first by DEBIAN-CVE-2026-110353, released October 25, 2026. It is not reported as exploited. Patch Radar priority: High.

High
CVSS
7.5
high
Exploitation
None reported
No vendor assessment
CISA KEV
Not listed
Not in the Known Exploited Vulnerabilities catalog
EPSS
0.0074
54th percentile

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.

Where it's fixed

ProductFixed inFixReleased
Linux
haproxy · Debian 14 3.2.26-1 DEBIAN-CVE-2026-110353 Oct 25, 2026
haproxy · Ubuntu 22.04.1 LTS (jammy) 2.4.30-0ubuntu0.22.04.3 haproxy 2.4.30-0ubuntu0.22.04.3 Nov 4, 2026
haproxy · Ubuntu 24.04.5 LTS (noble) 2.8.30-0ubuntu0.24.04.2 haproxy 2.8.30-0ubuntu0.24.04.2 Nov 4, 2026
haproxy · Ubuntu 26.04.1 LTS (resolute) 3.2.25-0ubuntu0.26.04.2 haproxy 3.2.25-0ubuntu0.26.04.2 Nov 7, 2026
vim-haproxy · Ubuntu 22.04.1 LTS (jammy) 2.4.30-0ubuntu0.22.04.3 vim-haproxy 2.4.30-0ubuntu0.22.04.3 Nov 4, 2026
vim-haproxy · Ubuntu 24.04.5 LTS (noble) 2.8.30-0ubuntu0.24.04.2 vim-haproxy 2.8.30-0ubuntu0.24.04.2 Nov 4, 2026
vim-haproxy · Ubuntu 26.04.1 LTS (resolute) 3.2.25-0ubuntu0.26.04.2 vim-haproxy 3.2.25-0ubuntu0.26.04.2 Nov 7, 2026

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