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

highCVSS 7.5CVE-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.

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-2026-54428

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-2026-544280.59% 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-2026-54428	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 Allocation of resources

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-2026-40006: Memory Allocation with Excessive Size Value, Allocation of Resources Without Limits or Throttl…nvd · 2026-07-10
highCVE-2026-31984: A denial-of-service vulnerability caused by unbounded resource allocation was discovered in th…nvd · 2026-07-09
highCVE-2026-56811: Allocation of Resources Without Limits or Throttling vulnerability in phoenixframework phoenix…nvd · 2026-07-07
unknownCVE-2026-56810: Allocation of Resources Without Limits or Throttling vulnerability in elixir-mint mint (Mint.H…nvd · 2026-07-06
mediumCVE-2026-56149: Allocation of Resources Without Limits or Throttling in Elasticsearch Leading to Denial of Ser…msrc · 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