CVE-2026-54399: 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

highCVSS 7.5CVE-2026-54399

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

Details

Source: NVD Recent CVEs (US · database · site)
Severity: high — CVSS 7.5
Published: 2026-07-01
Last updated: 2026-07-06
Exploitation: Not in CISA KEV at last sync

Original advisory: https://nvd.nist.gov/vuln/detail/CVE-2026-54399

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

Low exploitation riskCVE-2026-543990.59% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 44% of all scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-54399	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.

medium[NEW] [medium] Apache HttpComponents Core: Multiple vulnerabilities allow Denial of Servicecert-bund

Recent advisories for Uncontrolled Resource Consumption

A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.

highCVE-2026-40007: Uncontrolled Recursion, Uncontrolled Resource Consumption vulnerability in Apache IoTDB. When …nvd · 2026-07-10
highCVE-2026-24012: Uncontrolled Resource Consumption vulnerability in Apache IoTDB. Some interface fails to impos…nvd · 2026-07-06
mediumCVE-2026-49090: Uncontrolled Resource Consumption in Elasticsearch Leading to Denial of Servicemsrc · 2026-07-02
mediumCVE-2026-49090: Uncontrolled Resource Consumption (CWE-400) in Elasticsearch can lead to a denial of service v…nvd · 2026-07-01
criticalexploitedCVE-2026-28318: SolarWinds Serv-U Uncontrolled Resource Consumption Vulnerabilitycisa-kev · 2026-06-05
lowGHSA-647r-72hf-4vmh: Code Index MCP is vulnerable to Uncontrolled Resource Consumptionghsa · 2026-06-03