What is CVE-2026-54428?

CVE-2026-54428 is a high-severity vulnerability in Apache Httpcomponents Core, classified under Uncontrolled Resource Consumption. CVSS score: 7.5/10. Published 2026-07-01.

How severe is CVE-2026-54428?

High severity. CVSS v3 base score is 7.5 out of 10.

Resource exhaustion in Apache Httpcomponents Core

CVE-2026-54428

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.

Vulnerability class: DoS (Denial of Service)

EPSS: 0.006 (44.6th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Affected products

Apache Httpcomponents_core — versions 5.5
Apache Software Foundation Httpcomponents Core — versions 5.5-alpha, 5.0-alpha

Weakness classification (CWE)

References

security@apache.org (vendor-advisory, Mitigation, Vendor Advisory)
af854a3a-2127-422b-91ae-364da2661108 (Third Party Advisory, Mitigation)

Frequently asked questions

What is CVE-2026-54428?: CVE-2026-54428 is a high-severity vulnerability in Apache Httpcomponents Core, classified under Uncontrolled Resource Consumption. CVSS score: 7.5/10. Published 2026-07-01.
How severe is CVE-2026-54428?: High severity. CVSS v3 base score is 7.5 out of 10.