CVE-2026-54399: Httpcore5 Denial of Service Vulnerability

HIGH
Advisory Identifier: GHSA-hf6x-8p5f-cgmf
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CVSS 7.5
CWE-400
Published
Advisory Summary

CVE-2026-54399 is a HIGH (CVSS 7.5) denial of service vulnerability (CWE-400: Uncontrolled Resource Consumption) affecting Httpcore5 libraries in the Maven ecosystem. The issue involves apache httpcomponents core http/1 header parsing can cause memory-exhaustion denial of service. Remediation is available by upgrading affected packages to version 5.4.3, 5.5-beta2.

CVE-2026-54399 at a Glance

CVE Identifier CVE-2026-54399
GHSA Identifier GHSA-hf6x-8p5f-cgmf
Severity HIGH
CVSS v3.1 Base Score 7.5
CWE Classification CWE-400: Uncontrolled Resource Consumption
Affected Product Httpcore5
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 7.5

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality None (C:N)
Integrity None (I:N)
Availability High (A:H)

How to Fix CVE-2026-54399

To remediate this vulnerability, upgrade all affected Httpcore5 dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

org.apache.httpcomponents.core5:httpcore5 fixed: 5.4.3 
<dependency>
    <groupId>org.apache.httpcomponents.core5</groupId>
    <artifactId>httpcore5</artifactId>
    <version>5.4.3</version>
</dependency>
org.apache.httpcomponents.core5:httpcore5 fixed: 5.5-beta2 
<dependency>
    <groupId>org.apache.httpcomponents.core5</groupId>
    <artifactId>httpcore5</artifactId>
    <version>5.5-beta2</version>
</dependency>
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

mvn dependency:tree -Dincludes=org.apache.httpcomponents.core5

How to Check if You Are Affected

To determine whether your Java application is affected by CVE-2026-54399, inspect your build dependencies using the Maven Dependency Plugin:

mvn dependency:tree -Dincludes=org.apache.httpcomponents.core5

Analyze the terminal output to locate any version of Httpcore5 in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 5.4.3), your application is affected.

Note: The mvn dependency:tree -Dincludes=org.apache.httpcomponents.core5 command inspects the resolved dependency graph declared in your project's POM files; it does not perform automated security scanning or inspect runtime dynamic classpaths. Always verify runtime container classpaths and shaded JARs.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-400: Uncontrolled Resource Consumption, where the product does not properly control the allocation and maintenance of a limited resource. In Httpcore5, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

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 a remote attacker to cause a denial of service through memory exhaustion by sending messages with excessive number of headers / excessive header length

CVE-2026-54399 Affected Httpcore5 Versions

2 component(s)
Fixed Versions:
5.4.35.5-beta2
Product / Package Ecosystem Affected Versions Fixed Version
org.apache.httpcomponents.core5:httpcore5
maven/org.apache.httpcomponents.core5/httpcore5
Maven
< 5.4.3
5.4.3
org.apache.httpcomponents.core5:httpcore5
maven/org.apache.httpcomponents.core5/httpcore5
Maven
≥ 5.5-alpha1
< 5.5-beta2
5.5-beta2

References

NVD — CVE-2026-54399 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-54399
Security Fix Commit FIX COMMIT
https://github.com/apache/httpcomponents-core/commit/d96a00fec9b2e19f8005e35681df5f6cd6e21a9e
Security Fix Commit FIX COMMIT
https://github.com/apache/httpcomponents-core/commit/fdc53a32fe0fccf098cc67e71cd125e447c759ed
Httpcore5 Source Repository REPOSITORY
https://github.com/apache/httpcomponents-core
lists.apache.org/thread/zmxh1pl2zoho... WEB
https://lists.apache.org/thread/zmxh1pl2zohov5ntdh4lt85gfrlchgpy
Httpcore5 Security Information SECURITY
http://www.openwall.com/lists/oss-security/2026/07/01/4

Frequently Asked Questions

What is CVE-2026-54399?
CVE-2026-54399 is a security vulnerability in Httpcore5 involving Apache HttpComponents Core HTTP/1 header parsing can cause memory-exhaustion denial of service under CWE-400: Uncontrolled Resource Consumption.
Which Httpcore5 versions are affected?
Affected versions include releases prior to 5.4.3, 5.5-beta2 across affected packages: org.apache.httpcomponents.core5:httpcore5.
What version fixes CVE-2026-54399?
Upgrading to 5.4.3, 5.5-beta2 (or the latest patched release for your respective branch) resolves the vulnerability.
Is httpcore5 affected?
Yes, org.apache.httpcomponents.core5:httpcore5 is affected in releases prior to 5.4.3, 5.5-beta2. Upgrade your dependency to 5.4.3, 5.5-beta2 or later.
What is the CVSS score of CVE-2026-54399?
CVE-2026-54399 has a CVSS v3.1 base score of 7.5 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
What CWE is associated with CVE-2026-54399?
CVE-2026-54399 is classified under CWE-400: Uncontrolled Resource Consumption (The product does not properly control the allocation and maintenance of a limited resource.).
How can I check Maven dependencies for CVE-2026-54399?
Run the dependency tree command: 'mvn dependency:tree -Dincludes=org.apache.httpcomponents.core5'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-hf6x-8p5f-cgmf",
  "modified" : "2026-08-12T19:24:45Z",
  "published" : "2026-07-01T18:31:55Z",
  "aliases" : [ "CVE-2026-54399" ],
  "summary" : "Apache HttpComponents Core HTTP/1 header parsing can cause memory-exhaustion denial of service",
  "details" : "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 a remote attacker to cause a denial of service through memory exhaustion by sending messages with excessive number of headers / excessive header length",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "org.apache.httpcomponents.core5:httpcore5"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "5.4.3"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "org.apache.httpcomponents.core5:httpcore5"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "5.5-alpha1"
      }, {
        "fixed" : "5.5-beta2"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-54399"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/apache/httpcomponents-core/commit/d96a00fec9b2e19f8005e35681df5f6cd6e21a9e"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/apache/httpcomponents-core/commit/fdc53a32fe0fccf098cc67e71cd125e447c759ed"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/apache/httpcomponents-core"
  }, {
    "type" : "WEB",
    "url" : "https://lists.apache.org/thread/zmxh1pl2zohov5ntdh4lt85gfrlchgpy"
  }, {
    "type" : "WEB",
    "url" : "http://www.openwall.com/lists/oss-security/2026/07/01/4"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-400" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-08-12T19:24:45Z",
    "nvd_published_at" : "2026-07-01T17:16:36Z"
  }
}