CVE-2026-54428

HIGH

Apache HttpComponents Core: HPackDecoder Unlimited Header List Size Before SETTINGS ACK

Title source: cna

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.

References (2)

Core 2

Core References

Vendor Advisory vendor-advisory

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

Mailing List

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

Scores

CVSS v3 7.5

EPSS 0.0059

EPSS Percentile 44.0%

Attack Vector NETWORK

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CISA SSVC

Vulnrichment

Exploitation none

Automatable yes

Technical Impact partial

Details

CWE

CWE-400 CWE-770

Status published

Products (4)

apache/httpcomponents_core 5.5 alpha1 (2 CPE variants)

apache/httpcomponents_core < 5.4.2

Apache Software Foundation/Apache HttpComponents Core 5.0-alpha - 5.4.2

Apache Software Foundation/Apache HttpComponents Core 5.5-alpha - 5.5-beta1

Published Jul 01, 2026

Tracked Since Jul 01, 2026