CVE-2026-54428 — Apache HttpComponents Core: HPackDecoder Unlimited Header List Size Before SETTINGS ACK

Description (CNA)

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.

Affected (CNA)

Vendor / product	Versions
Apache Software Foundation / Apache HttpComponents Core	affected 5.5-alpha through 5.5-beta1; affected 5.0-alpha through 5.4.2

CWE

CWE-770, CWE-400

References

https://lists.apache.org/thread/5zjp8vczvxq19pw2rvhs21q446bhl0sd

ADP enrichment

CVE

No English description supplied.

http://www.openwall.com/lists/oss-security/2026/07/01/3

CISA-ADP

No English description supplied.

No references supplied.