CVE-2026-26080 Denial of service in HAProxy
An attacker can cause HAProxy to crash or enter an infinite loop by exploiting a varint handling error, leading to service disruption.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-26080?
CVE-2026-26080 is a low-severity denial of service vulnerability in HAProxy, published on 20 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
HAProxy Community Edition 3.2.x through 3.3.x before 3.3.3 can enter a loop or crash because varint is mishandled. HAProxy Enterprise and ALOHA are also affected.
Weakness: CWE-252
Which versions are affected by CVE-2026-26080?
1 open source package ship an affected version, including haproxy. It affects 3 products.
| Package | Affected | Fixed in |
|---|---|---|
haproxy Bitnami | From 3.2.0 | 3.2.12, 3.3.3 |
Products include Haproxy Aloha, Haproxy Haproxy, Haproxy Haproxy Enterprise.
How do I fix CVE-2026-26080?
Upgrade haproxy to a fixed version for your release line: 3.2.12 or 3.3.3.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-26080 being exploited?
There is no known exploitation of CVE-2026-26080 in the wild and no public exploit code.
Public exploit code: 1 proofs of concept on GitHub.
Other vulnerabilities in HAProxy
Sources
Also known as BIT-haproxy-2026-26080, DEBIAN-CVE-2026-26080, GHSA-fhrv-3q89-79q6, MINI-4gg7-p72g-5hq2, MINI-cpxr-566v-7v76.