CVE-2026-54428
Apache HttpComponents Core: HPackDecoder Unlimited Header List Size Before SETTINGS ACK
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.
INFO
Published Date :
July 1, 2026, 6:16 p.m.
Last Modified :
July 24, 2026, 8:03 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | HIGH | 134c704f-9b21-4f2e-91b3-4a467353bcc0 |
Solution
- Update Apache HttpComponents Core to version 5.4.3 or later.
- Update Apache HttpComponents Core to version 5.5 or later.
Public PoC/Exploit Available at Github
CVE-2026-54428 has a 1 public
PoC/Exploit available at Github.
Go to the Public Exploits tab to see the list.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-54428.
| URL | Resource |
|---|---|
| https://lists.apache.org/thread/5zjp8vczvxq19pw2rvhs21q446bhl0sd | Mitigation Vendor Advisory |
| http://www.openwall.com/lists/oss-security/2026/07/01/3 | Mitigation Third Party Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-54428 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-54428
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
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Java Shell Python Dockerfile Batchfile
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-54428 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-54428 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Reanalysis by [email protected]
Jul. 24, 2026
Action Type Old Value New Value Changed CPE Configuration OR *cpe:2.3:a:apache:httpcomponents_core:5.5:beta1:*:*:*:*:*:* *cpe:2.3:a:apache:httpcomponents_core:*:*:*:*:*:*:*:* versions up to (including) 5.4.2 *cpe:2.3:a:apache:httpcomponents_core:5.5:alpha1:*:*:*:*:*:* OR *cpe:2.3:a:apache:httpcomponents_core:5.5:beta1:*:*:*:*:*:* *cpe:2.3:a:apache:httpcomponents_core:5.5:alpha1:*:*:*:*:*:* *cpe:2.3:a:apache:httpcomponents_core:*:*:*:*:*:*:*:* versions from (including) 5.0 up to (including) 5.4.2 -
Initial Analysis by [email protected]
Jul. 06, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:a:apache:httpcomponents_core:5.5:beta1:*:*:*:*:*:* *cpe:2.3:a:apache:httpcomponents_core:*:*:*:*:*:*:*:* versions up to (including) 5.4.2 *cpe:2.3:a:apache:httpcomponents_core:5.5:alpha1:*:*:*:*:*:* Added Reference Type Apache Software Foundation: https://lists.apache.org/thread/5zjp8vczvxq19pw2rvhs21q446bhl0sd Types: Mitigation, Vendor Advisory Added Reference Type CVE: http://www.openwall.com/lists/oss-security/2026/07/01/3 Types: Mitigation, Third Party Advisory -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jul. 01, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Added SSVC {'id': 'CVE-2026-54428', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'yes'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-07-01T18:15:24.114171Z'} -
New CVE Received by [email protected]
Jul. 01, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'Apache Software Foundation', 'product': 'Apache HttpComponents Core', 'versions': [{'status': 'affected', 'version': '5.5-alpha', 'versionType': 'maven', 'lessThanOrEqual': '5.5-beta1'}, {'status': 'affected', 'version': '5.0-alpha', 'versionType': 'maven', 'lessThanOrEqual': '5.4.2'}], 'packageName': 'org.apache.httpcomponents.core5:httpcore5-h2', 'collectionURL': 'https://repo.maven.apache.org/maven2/', 'defaultStatus': 'unaffected'}] Added 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. Added CWE CWE-400 Added CWE CWE-770 Added Reference https://lists.apache.org/thread/5zjp8vczvxq19pw2rvhs21q446bhl0sd -
CVE Modified by af854a3a-2127-422b-91ae-364da2661108
Jul. 01, 2026
Action Type Old Value New Value Added Reference http://www.openwall.com/lists/oss-security/2026/07/01/3