Amazon Linux 2023 Security Advisory: ALAS2023-2026-1915
Advisory Released Date: 2026-07-07
Advisory Updated Date: 2026-07-07
Severity:
Important
Issue Overview:
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. (CVE-2026-55204)
Affected Packages:
haproxy
Issue Correction:
Run dnf update haproxy --releasever 2023.12.20260706 or dnf update --advisory ALAS2023-2026-1915 --releasever 2023.12.20260706 to update your system.
More information on how to update your system can be found on this page: Amazon Linux 2023 documentation
New Packages:
aarch64:
haproxy-debuginfo-3.0.23-2.amzn2023.0.1.aarch64
haproxy-3.0.23-2.amzn2023.0.1.aarch64
haproxy-debugsource-3.0.23-2.amzn2023.0.1.aarch64
src:
haproxy-3.0.23-2.amzn2023.0.1.src
x86_64:
haproxy-debuginfo-3.0.23-2.amzn2023.0.1.x86_64
haproxy-3.0.23-2.amzn2023.0.1.x86_64
haproxy-debugsource-3.0.23-2.amzn2023.0.1.x86_64