#VU107589 Heap-based buffer overflow in HAProxy - CVE-2025-32464

Vulnerability identifier: #VU107589

Vulnerability risk: Low

CVSSv4.0: 4.6 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2025-32464

CWE-ID: CWE-122

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
HAProxy
Server applications / IDS/IPS systems, Firewalls and proxy servers

Vendor: HAProxy

Description

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to a boundary error within the regsub() function in src/sample.c. A remote attacker can pass specially crafted data to the application, trigger a heap-based buffer overflow and perform a denial of service (DoS) attack.

Successful exploitation of this vulnerability requires a very specific configuration of the proxy server.

Mitigation
Cybersecurity Help is currently unaware of any official solution to address this vulnerability.

Vulnerable software versions

HAProxy: 2.2.0 - 2.2.33, 2.3.0 - 2.3.21, 2.4.0 - 2.4.28, 2.5.0 - 2.5.14, 2.6.0 - 2.6.21, 2.7.0 - 2.7.12, 2.8.0 - 2.8.11, 2.9.0 - 2.9.15, 3.0.0 - 3.0.9, 3.1.0

---

External links
https://github.com/haproxy/haproxy/commit/3e3b9eebf871510aee36c3a3336faac2f38c9559

---

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.