HAProxy vulnerabilities: known CVEs & security history
HAProxy · Infrastructure · 5 tracked CVEs · 0 actively exploited · updated September 2026 · what is a CVE? →
This is the full list of known vulnerabilities (CVEs) across all HAProxy release lines — 5 in total. A CVE here doesn't mean your version is affected — check HAProxy's current status and the safe version to run.
Known HAProxy CVEs
Actively-exploited and most-severe first. Open any CVE for full details.
| CVE | Severity | CVSS | EPSS | Year |
|---|---|---|---|---|
| CVE-2026-55204 | high | 7.5 | 0% | 2026 |
| CVE-2026-55203 | high | 7.5 | 0% | 2026 |
| CVE-2026-26081 | medium | 4.8 | 0% | 2026 |
| CVE-2026-33555 | medium | 4 | 0% | 2026 |
| CVE-2026-26080 | low | 3.7 | 1% | 2026 |
Is my HAProxy version affected?
The list above spans every release. To know whether your version is affected — and the minimum safe version to upgrade to — check it directly.
Check your HAProxy version → · Monitor HAProxy for new CVEs →
HAProxy vulnerabilities — frequently asked
How many known vulnerabilities does HAProxy have?
IsItPatched tracks 5 CVEs for HAProxy. 0 are critical-severity and 2 high-severity. These span every release line — what matters is whether the version you run is affected.
Does HAProxy have any actively-exploited vulnerabilities?
None of HAProxy's tracked CVEs are currently in CISA's KEV catalog — but new ones can be added at any time, so keep your version current.
What is the most severe HAProxy vulnerability?
Among tracked issues, CVE-2026-55204 (HIGH, CVSS 7.5) ranks highest — a CWE-476 weakness.
Is HAProxy safe to use?
It depends on the version. The latest supported HAProxy release (3.4.3) clears the known issues; older versions may still be affected. Check the exact version you run for a verdict.
CVE data aggregated from NVD, CISA KEV and EPSS (FIRST.org). Related: HAProxy security status · HAProxy end-of-life · actively-exploited CVEs. Always verify against HAProxy's advisories — see our disclaimer.