#VU122782 Integer underflow in HAProxy - CVE-2026-26081
Published: February 12, 2026
Vulnerability identifier: #VU122782
Vulnerability risk: Medium
CVSSv4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-26081
CWE-ID: CWE-191
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerable software:
HAProxy
HAProxy
Software vendor:
HAProxy
HAProxy
Description
The vulnerability allows a remote attacker to perform a denial of service attack.
The vulnerability exists due to integer underflow when handling QUIC packets. A remote attacker can send a specially crafted request to the server, trigger an integer underflow and perform a denial of service attack.
Remediation
Install updates from vendor's website.
External links
- https://www.mail-archive.com/haproxy@formilux.org/msg46589.html
- https://www.haproxy.com/blog/cves-2026-quic-denial-of-service
- https://git.haproxy.org/?p=haproxy-3.0.git;a=commit;h=a05eade0f07483e6b6d0b61b1749e9093647e802
- https://git.haproxy.org/?p=haproxy-3.2.git;a=commit;h=4765277f4f915baac2d57db63538ff0a59966deb