CVE-2026-11856: Software Security Vulnerability Vulnerability

CRITICAL
Advisory Identifier: GHSA-9crq-qh8v-6xmm
Share
CVSS 9.8
CWE-294
Published
Advisory Summary

CVE-2026-11856 is a CRITICAL (CVSS 9.8) security vulnerability vulnerability (CWE-294: Authentication Bypass by Capture-replay) affecting Software libraries in the Maven ecosystem. The weakness occurs when a capture-replay flaw exists when the design of the product makes it possible for a malicious user to sniff network traffic and bypass authentication by replaying it to the server in question to the same effect as the original message (or with minor changes).. Remediation is available in the latest vendor maintenance releases.

CVE-2026-11856 at a Glance

CVE Identifier CVE-2026-11856
GHSA Identifier GHSA-9crq-qh8v-6xmm
Severity CRITICAL
CVSS v3.1 Base Score 9.8
CWE Classification CWE-294: Authentication Bypass by Capture-replay
Affected Product Software
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 9.8

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:H/I:H/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 High (C:H)
Integrity High (I:H)
Availability High (A:H)

How to Fix CVE-2026-11856

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

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

How to Check if You Are Affected

To determine whether your Java application is affected by CVE-2026-11856, inspect your build dependencies using the Maven Dependency Plugin:

mvn dependency:tree

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

Note: The mvn dependency:tree 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-294: Authentication Bypass by Capture-replay, where a capture-replay flaw exists when the design of the product makes it possible for a malicious user to sniff network traffic and bypass authentication by replaying it to the server in question to the same effect as the original message (or with minor changes). In Software, 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

Successfully using libcurl to do a transfer to a specific HTTP origin (`hostA`) with **Digest** authentication and then changing the origin to a different one (`hostB`) for a second transfer, reusing the same handle, makes libcurl wrongly pass on the `Authorization:` header field meant for `hostA`, to `hostB`.

References

NVD — CVE-2026-11856 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-11856
hackerone.com/reports/3793260 WEB
https://hackerone.com/reports/3793260
curl.se/docs/cve-2026-11856... WEB
https://curl.se/docs/CVE-2026-11856.html
curl.se/docs/cve-2026-11856... WEB
https://curl.se/docs/CVE-2026-11856.json

Frequently Asked Questions

What is CVE-2026-11856?
CVE-2026-11856 is a security vulnerability in Software classified as a security vulnerability vulnerability under CWE-294: Authentication Bypass by Capture-replay.
Which Software versions are affected?
Affected versions include releases prior to current release patches.
What version fixes CVE-2026-11856?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What is the CVSS score of CVE-2026-11856?
CVE-2026-11856 has a CVSS v3.1 base score of 9.8 (CRITICAL) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
What CWE is associated with CVE-2026-11856?
CVE-2026-11856 is classified under CWE-294: Authentication Bypass by Capture-replay (A capture-replay flaw exists when the design of the product makes it possible for a malicious user to sniff network traffic and bypass authentication by replaying it to the server in question to the same effect as the original message (or with minor changes).).
How can I check Maven dependencies for CVE-2026-11856?
Run the dependency tree command: 'mvn dependency:tree'. 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-9crq-qh8v-6xmm",
  "modified" : "2026-07-06T21:30:31Z",
  "published" : "2026-07-03T09:31:26Z",
  "aliases" : [ "CVE-2026-11856" ],
  "details" : "Successfully using libcurl to do a transfer to a specific HTTP origin\n(`hostA`) with **Digest** authentication and then changing the origin to a\ndifferent one (`hostB`) for a second transfer, reusing the same handle, makes\nlibcurl wrongly pass on the  `Authorization:` header field meant for `hostA`,\nto `hostB`.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
  } ],
  "affected" : [ ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-11856"
  }, {
    "type" : "WEB",
    "url" : "https://hackerone.com/reports/3793260"
  }, {
    "type" : "WEB",
    "url" : "https://curl.se/docs/CVE-2026-11856.html"
  }, {
    "type" : "WEB",
    "url" : "https://curl.se/docs/CVE-2026-11856.json"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-294" ],
    "severity" : "CRITICAL",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-07-03T07:16:23Z"
  }
}