CVE-2026-81905: Software Security Vulnerability Vulnerability

MODERATE
Advisory Identifier: GHSA-xgp3-243g-wxvm
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CWE-640
Published
Advisory Summary

CVE-2026-81905 is a MODERATE security vulnerability vulnerability (CWE-640: Weak Password Recovery Mechanism for Forgotten Password) affecting Software libraries in the Maven ecosystem. The weakness occurs when the product contains a mechanism for users to recover or change their passwords without knowing the original password, but the mechanism is weak.. Remediation is available in the latest vendor maintenance releases.

CVE-2026-81905 at a Glance

CVE Identifier CVE-2026-81905
GHSA Identifier GHSA-xgp3-243g-wxvm
Severity MODERATE
CVSS v3.1 Base Score N/A
CWE Classification CWE-640: Weak Password Recovery Mechanism for Forgotten Password
Affected Product Software
Package Ecosystem Maven
Published Date
Last Updated

How to Fix CVE-2026-81905

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-2026-81905, 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-640: Weak Password Recovery Mechanism for Forgotten Password, where the product contains a mechanism for users to recover or change their passwords without knowing the original password, but the mechanism is weak. 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

Concrete CMS below 9.5.3 stores user validation hashes for multiple purposes (email/registration validation, password reset, and persistent login) in a single table with a type column, but the redemption path resolves a hash by value alone and does not verify its type. As a result, a hash issued for one purpose can be redeemed for another: a long-lived registration hash (60-day expiry) can be submitted to the password-change endpoint to set a new password on the target account, and a password-reset hash can be submitted to the email-validation endpoint to activate an account. Exploitation requires the attacker to first obtain a valid hash through a separate channel (for example email interception, log exposure, or SSRF against an internal mail relay), so the flaw amplifies the impact of any hash disclosure rather than creating a standalone entry point. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 6.3 with vector CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N. Thanks Yonatan Drori from Tenzai for reporting.

References

NVD — CVE-2026-81905 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-81905
documentation.concretecms.org/developers/introduc... WEB
https://documentation.concretecms.org/developers/introduction/version-history/953-release-notes

Frequently Asked Questions

What is CVE-2026-81905?
CVE-2026-81905 is a security vulnerability in Software classified as a security vulnerability vulnerability under CWE-640: Weak Password Recovery Mechanism for Forgotten Password.
Which Software versions are affected?
Affected versions include releases prior to current release patches.
What version fixes CVE-2026-81905?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What CWE is associated with CVE-2026-81905?
CVE-2026-81905 is classified under CWE-640: Weak Password Recovery Mechanism for Forgotten Password (The product contains a mechanism for users to recover or change their passwords without knowing the original password, but the mechanism is weak.).
How can I check Maven dependencies for CVE-2026-81905?
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-xgp3-243g-wxvm",
  "modified" : "2026-09-11T00:31:16Z",
  "published" : "2026-09-11T00:31:16Z",
  "aliases" : [ "CVE-2026-81905" ],
  "details" : "Concrete CMS below 9.5.3 stores user validation hashes for multiple purposes (email/registration validation, password reset, and persistent login) in a single table with a type column, but the redemption path resolves a hash by value alone and does not verify its type. As a result, a hash issued for one purpose can be redeemed for another: a long-lived registration hash (60-day expiry) can be submitted to the password-change endpoint to set a new password on the target account, and a password-reset hash can be submitted to the email-validation endpoint to activate an account. Exploitation requires the attacker to first obtain a valid hash through a separate channel (for example email interception, log exposure, or SSRF against an internal mail relay), so the flaw amplifies the impact of any hash disclosure rather than creating a standalone entry point. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 6.3 with vector CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N. Thanks Yonatan Drori from Tenzai for reporting.",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X"
  } ],
  "affected" : [ ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-81905"
  }, {
    "type" : "WEB",
    "url" : "https://documentation.concretecms.org/developers/introduction/version-history/953-release-notes"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-640" ],
    "severity" : "MODERATE",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-09-11T00:19:48Z"
  }
}