CVE-2026-110353: HAProxy 3.2 before 3.4.6 allows a remote unauthenticated attacker to cause a denial of service (worker-thread
44
This month
HIGH 7.5REMOTE
CVE-2026-110353 is a high-severity flaw (CVSS 7.5) affecting affected software. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
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
Why this priority
- High severity
- Remotely exploitable, no login, no user action
A fixed release or distro patch exists.
Risk facts
| CVSS score | 7.5 (High) |
| Attack vector | Network (remote) |
| Attack complexity | Low |
| Privileges needed | None |
| User interaction | None |
| EPSS exploit chance | 0.7% (top 48%) |
| CISA exploited list | No |
| Weakness | CWE-252 |
| Published | 2026-10-22 |
| Last modified | 2026-10-22 |
Publisher (CNA): MITRE
Timeline
- Published CVE record published
- Updated Record last modified
Exact fixes by distribution
Fedora 46 · kwin-zones · FIXED · 1.0.13-1.fc46 · FEDORA-2026-95888f332b · source
sudo dnf upgrade --advisory=FEDORA-2026-95888f332b
Fedora ELN · nginx-mod-brotli · FIXED · 1.0.0~rc-16.eln159 · FEDORA-2026-501a6a8273 · source
sudo dnf upgrade --advisory=FEDORA-2026-501a6a8273
RHEL 10 · haproxy · NO FIX YET
RHEL 7 · haproxy · NO FIX YET
RHEL 8 · haproxy · NO FIX YET
RHEL 9 · haproxy · NO FIX YET
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Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.