CVE-2026-54399: Apache Httpcomponents Core

High severity, CVSS 7.5. EPSS: 0.9% chance of exploitation in the next 30 days.

Uncontrolled Resource Consumption vulnerability in the HTTP/1.1 message parser 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 messages with excessive number of headers / excessive header length

Affected products

• Apache Httpcomponents Core: from 5.0, up to and including 5.4.2; version 5.5 only

Published 2026-07-01. Last modified 2026-07-24.