This page tracks the Debian fix status. The vulnerability itself is described on the main CVE page. View CVE-2026-55204 →

DEBIAN-CVE-2026-55204

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 f...

Original description

The description as published by the source.

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.

Source: OSV.dev (Open Source Vulnerabilities) OSV

Affected packages

Debian:12 haproxy

[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]

Debian:13 haproxy

[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]

Debian:14 haproxy

[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.2.20-1"}]}]

References

advisory security-tracker.debian.org