CVE-2026-6656: Software Security Vulnerability Vulnerability

HIGH
Advisory Identifier: GHSA-c9g9-v2j9-8ffv
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CVSS 7.5
CWE-208
Published
Advisory Summary

CVE-2026-6656 is a HIGH (CVSS 7.5) security vulnerability vulnerability (CWE-208: Observable Timing Discrepancy) affecting Software libraries in the Maven ecosystem. The weakness occurs when two separate operations in a product require different amounts of time to complete, in a way that is observable to an actor and reveals security-relevant information about the state of the product, such as whether a particular operation was successful or not.. Remediation is available in the latest vendor maintenance releases.

CVE-2026-6656 at a Glance

CVE Identifier CVE-2026-6656
GHSA Identifier GHSA-c9g9-v2j9-8ffv
Severity HIGH
CVSS v3.1 Base Score 7.5
CWE Classification CWE-208: Observable Timing Discrepancy
Affected Product Software
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:H/I:N/A:N).

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 None (I:N)
Availability None (A:N)

How to Fix CVE-2026-6656

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-2026-6656, 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-208: Observable Timing Discrepancy, where two separate operations in a product require different amounts of time to complete, in a way that is observable to an actor and reveals security-relevant information about the state of the product, such as whether a particular operation was successful or not. 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

Crypt::Password versions through 0.28 for Perl are susceptible to timing attacks. The check_password method uses the built-in eq operator. This allows discrepancies in timing to be used to guess the underlying hash.

References

NVD — CVE-2026-6656 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-6656
metacpan.org/release/drsteve/cry... WEB
https://metacpan.org/release/DRSTEVE/Crypt-Password-0.28/source/lib/Crypt/Password.pm#L190-193
rt.cpan.org/ticket/display.html WEB
https://rt.cpan.org/Ticket/Display.html?id=180162
Software Security Information SECURITY
http://www.openwall.com/lists/oss-security/2026/07/20/4

Frequently Asked Questions

What is CVE-2026-6656?
CVE-2026-6656 is a security vulnerability in Software classified as a security vulnerability vulnerability under CWE-208: Observable Timing Discrepancy.
Which Software versions are affected?
Affected versions include releases prior to current release patches.
What version fixes CVE-2026-6656?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What is the CVSS score of CVE-2026-6656?
CVE-2026-6656 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:H/I:N/A:N.
What CWE is associated with CVE-2026-6656?
CVE-2026-6656 is classified under CWE-208: Observable Timing Discrepancy (Two separate operations in a product require different amounts of time to complete, in a way that is observable to an actor and reveals security-relevant information about the state of the product, such as whether a particular operation was successful or not.).
How can I check Maven dependencies for CVE-2026-6656?
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-c9g9-v2j9-8ffv",
  "modified" : "2026-07-20T21:31:44Z",
  "published" : "2026-07-20T09:31:08Z",
  "aliases" : [ "CVE-2026-6656" ],
  "details" : "Crypt::Password versions through 0.28 for Perl are susceptible to timing attacks.\n\nThe check_password method uses the built-in eq operator. This allows discrepancies in timing to be used to guess the underlying hash.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N"
  } ],
  "affected" : [ ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-6656"
  }, {
    "type" : "WEB",
    "url" : "https://metacpan.org/release/DRSTEVE/Crypt-Password-0.28/source/lib/Crypt/Password.pm#L190-193"
  }, {
    "type" : "WEB",
    "url" : "https://rt.cpan.org/Ticket/Display.html?id=180162"
  }, {
    "type" : "WEB",
    "url" : "http://www.openwall.com/lists/oss-security/2026/07/20/4"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-208" ],
    "severity" : "HIGH",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-07-20T07:16:42Z"
  }
}