Vulnerability in Haproxy
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 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.
Published · last modified .
CVSS v3 metric
CVSS v3 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.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
Weakness classification (CWE)
References
- git.haproxy.org/ (vendor-advisory)
Frequently asked questions
- What is CVE-2026-110353?
- CVE-2026-110353 is a high-severity vulnerability in Haproxy, classified under CWE-252. CVSS score: 7.5/10. Published 2026-10-22.
- How severe is CVE-2026-110353?
- High severity. CVSS v3 base score is 7.5 out of 10.