CVE-2026-15806: Software Security Vulnerability Vulnerability

MODERATE
Advisory Identifier: GHSA-2v69-2w5x-455j
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CWE-319
Published
Advisory Summary

CVE-2026-15806 is a MODERATE security vulnerability vulnerability (CWE-319: Cleartext Transmission of Sensitive Information) affecting Software libraries in the Maven ecosystem. The weakness occurs when the product transmits sensitive or security-critical data in cleartext in a communication channel that can be sniffed by unauthorized actors.. Remediation is available in the latest vendor maintenance releases.

CVE-2026-15806 at a Glance

CVE Identifier CVE-2026-15806
GHSA Identifier GHSA-2v69-2w5x-455j
Severity MODERATE
CVSS v3.1 Base Score N/A
CWE Classification CWE-319: Cleartext Transmission of Sensitive Information
Affected Product Software
Package Ecosystem Maven
Published Date
Last Updated

How to Fix CVE-2026-15806

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-2026-15806, 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-319: Cleartext Transmission of Sensitive Information, where the product transmits sensitive or security-critical data in cleartext in a communication channel that can be sniffed by unauthorized actors. 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

The HTTPPasswordMgr class in the urllib.request module, along with its subclasses HTTPPasswordMgrWithDefaultRealm and HTTPPasswordMgrWithPriorAuth, did not take the URL scheme into account when matching stored credentials against a requested URL. Credentials added for an https:// URL were also used for requests to the same host over http://, so an attacker able to redirect or downgrade a client to plain HTTP (for example, via an HTTPS-to-HTTP redirect or an on-path position) could capture credentials in cleartext. Credentials added for http:// URLs could likewise be sent over https://. Credential matching is now scoped by URL scheme. Credentials registered with a URL that includes a scheme are only used for requests with the same scheme. Credentials registered with a bare authority (such as example.com or example.com:8080) continue to match any scheme, preserving compatibility with existing code, including proxy authentication. Users who cannot upgrade immediately can mitigate by ensuring that applications never make plain http:// requests to hosts for which credentials are registered, for example by not following redirects to http:// URLs.

References

NVD — CVE-2026-15806 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-15806
Software Source Repository REPOSITORY
https://github.com/python/cpython/issues/155694
Software Source Repository REPOSITORY
https://github.com/python/cpython/pull/155696
Security Fix Commit FIX COMMIT
https://github.com/python/cpython/commit/641be42bb07921ba0f8bffe228b1dc706b092ef6
Security Fix Commit FIX COMMIT
https://github.com/python/cpython/commit/851cf9a7142ecbdd39f831055533f58284ad2bcc
Security Fix Commit FIX COMMIT
https://github.com/python/cpython/commit/95355ee3a8e1d3c3d4858d1973aa42a9b91a2801
Security Fix Commit FIX COMMIT
https://github.com/python/cpython/commit/a0d023fbd23773e24b35d8368789470e22cda5d8
Security Fix Commit FIX COMMIT
https://github.com/python/cpython/commit/a2773a34183b7d94a243bb98fd658926cc5348ce
Security Fix Commit FIX COMMIT
https://github.com/python/cpython/commit/a7bb524fef61f77ede01f660ffbd591e1d5837ce
Security Fix Commit FIX COMMIT
https://github.com/python/cpython/commit/dac88d8615078c55f1304ea4c7a2d822700d4e5a
Software Security Information SECURITY
https://mail.python.org/archives/list/security-announce@python.org/thread/3OKPE5S75KDNA7FY7AI3PL2MXM2X5RB3
Software Security Information SECURITY
http://www.openwall.com/lists/oss-security/2026/08/18/3

Frequently Asked Questions

What is CVE-2026-15806?
CVE-2026-15806 is a security vulnerability in Software classified as a security vulnerability vulnerability under CWE-319: Cleartext Transmission of Sensitive Information.
Which Software versions are affected?
Affected versions include releases prior to current release patches.
What version fixes CVE-2026-15806?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What CWE is associated with CVE-2026-15806?
CVE-2026-15806 is classified under CWE-319: Cleartext Transmission of Sensitive Information (The product transmits sensitive or security-critical data in cleartext in a communication channel that can be sniffed by unauthorized actors.).
How can I check Maven dependencies for CVE-2026-15806?
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 
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  "id" : "GHSA-2v69-2w5x-455j",
  "modified" : "2026-10-01T03:31:11Z",
  "published" : "2026-08-18T18:31:57Z",
  "aliases" : [ "CVE-2026-15806" ],
  "details" : "The HTTPPasswordMgr class in the urllib.request module, along with its subclasses HTTPPasswordMgrWithDefaultRealm and HTTPPasswordMgrWithPriorAuth, did not take the URL scheme into account when matching stored credentials against a requested URL. Credentials added for an https:// URL were also used for requests to the same host over http://, so an attacker able to redirect or downgrade a client to plain HTTP (for example, via an HTTPS-to-HTTP redirect or an on-path position) could capture credentials in cleartext. Credentials added for http:// URLs could likewise be sent over https://.\n\nCredential matching is now scoped by URL scheme. Credentials registered with a URL that includes a scheme are only used for requests with the same scheme. Credentials registered with a bare authority (such as example.com or example.com:8080) continue to match any scheme, preserving compatibility with existing code, including proxy authentication.\n\nUsers who cannot upgrade immediately can mitigate by ensuring that applications never make plain http:// requests to hosts for which credentials are registered, for example by not following redirects to http:// URLs.",
  "severity" : [ {
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    "url" : "http://www.openwall.com/lists/oss-security/2026/08/18/3"
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    "nvd_published_at" : "2026-08-18T16:17:02Z"
  }
}