PT-2026-50708 · Haproxy · Haproxy

Tristan Madani · Published 2026-06-18 · Updated 2026-06-18 · CVE-2026-55204

NVD

CVSS v3.1

7.5

High

Base vector

AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

HAProxy through 3.4.0, fixed in commit 9a6d1fe, contains a null pointer dereference vulnerability in hpack dht insert() within src/hpack-tbl.c that fails to validate the return value of hpack dht defrag() when the memory pool is exhausted. An attacker can trigger HPACK dynamic table insertions under memory pressure to dereference a NULL pointer and crash HAProxy worker processes, causing denial of service.

Fix

NULL Pointer Dereference

Weakness Enumeration

CWE-476

Related Identifiers

CVE-2026-55204

Affected Products

Haproxy

References · 3

• https://github.com/haproxy/haproxy/commit/9a6d1fe3f00d86ab4ea6ea6ea0a5d48fc058a513 · Patch
• https://nvd.nist.gov/vuln/detail/CVE-2026-55204 · Security Note
• https://vulncheck.com/advisories/haproxy-null-pointer-dereference-in-hpack-dht-insert-function · Note