CVE-2026-54428

Name	CVE-2026-54428
Description	Allocation of resources without limits or throttling in the HTTP/2 HPACK decoder in Apache HttpComponents Core (5.4.2 and earlier, 5.5-beta1 and earlier) allows an remote attacker to cause a denial of service through memory exhaustion by sending oversized compressed header blocks before the HTTP/2 SETTINGS acknowledgement causes the configured header list size limit to be applied.
Source	CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
httpcomponents-core (PTS)	bullseye	4.4.14-1	vulnerable
	forky, sid, bookworm, trixie	4.4.16-1	vulnerable
httpcomponents-core5 (PTS)	bookworm	5.2.1-1	vulnerable
	trixie	5.2.2-1	vulnerable
	forky, sid	5.4.2-1.1	vulnerable

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
httpcomponents-core	source	(unstable)	(unfixed)
httpcomponents-core5	source	(unstable)	(unfixed)

https://www.openwall.com/lists/oss-security/2026/07/01/3
v4 possibly not affected, needs further validation once fix is identified