CVE-2021-26037Network attack vector

Session persistence after credential revocation

Published Jul 7, 2021 · Updated Feb 25, 2026

Incorrect session handling in Joomla! CMS 2.5.0 through 3.9.27 allows remote authenticated users to retain access after a password change or account block. Session-management functions fail to invalidate existing login sessions when credentials change or an account is disabled. An attacker must already possess a valid session, and the demonstrated consequence is continued authenticated access rather than code execution or service interruption.

CVSS severity5.3
Medium
EPSS probability0.85%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Incorrect session handling in Joomla! CMS 2.5.0 through 3.9.27 allows remote authenticated users to retain access after a password change or account block. Session-management functions fail to invalidate existing login sessions when credentials change or an account is disabled. An attacker must already possess a valid session, and the demonstrated consequence is continued authenticated access rather than code execution or service interruption.

The record

CVE
CVE-2021-26037
Published
Jul 7, 2021
Updated
Feb 25, 2026
Vendor
Joomla! Project
Product
Joomla! CMS
Classifications
CWE-613
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 7, 2021CVE publishedPublication date reported by the CVE source.
  2. Feb 25, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=2.5.0-3.9.27

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Joomla! Project · Joomla! CMSversion=2.5.0-3.9.27

Published CVSS scores

5.0NVDAV:N/AC:L/Au:N/C:N/I:P/A:N
5.3NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-613Insufficient Session Expiration

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo