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Vulnerability record · CVE-2021-3311 · published 5 February 2021

CVE-2021-3311: Octobercms october insufficient session expiration vulnerability

Octobercms · October

An issue was discovered in October through build 471. It reactivates an old session ID (which had been invalid after a logout) once a new login occurs. NOTE: this violates the intended Auth/Manager.php authentication behavior but, admittedly, is only relevant if an old session ID is known to an attacker.

9.8 CVSS 3.1 Critical EPSS 2.9% · top 13.6% CWE-613 · Insufficient session expiration
9.8CVSS 3.1 base score, v2 6.8
2.9%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
6References, 2 tagged exploit
17 Jun 2026Last modified by NVD

Description

An issue was discovered in October through build 471. It reactivates an old session ID (which had been invalid after a logout) once a new login occurs. NOTE: this violates the intended Auth/Manager.php authentication behavior but, admittedly, is only relevant if an old session ID is known to an attacker.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://anisiosantos.me/october-cms-token-reactivation ExploitThird Party Advisory
https://github.com/octobercms/library/commit/642f597489e6f644d4bd9a0c267e864cabead024 PatchThird Party Advisory
https://octobercms.com/forum/chan/announcements Vendor Advisory
https://anisiosantos.me/october-cms-token-reactivation ExploitThird Party Advisory
https://github.com/octobercms/library/commit/642f597489e6f644d4bd9a0c267e864cabead024 PatchThird Party Advisory
https://octobercms.com/forum/chan/announcements Vendor Advisory

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

9.1CVE-2021-32648October CMS password reset authentication bypassOctober CMS, a Laravel-based CMS, contains an improper authentication flaw in the october/system package. An attacker can request an account password…KEVEPSS 90%analysed9.8CVE-2017-1000194Octobercms october unrestricted file upload vulnerabilityOctober CMS build 412 is vulnerable to Apache configuration modification via file upload functionality resulting in site compromise and possibly othe…EPSS 1.2%9.8CVE-2017-1000196Octobercms october code injection vulnerabilityOctober CMS build 412 is vulnerable to PHP code execution in the asset manager functionality resulting in site compromise and possibly other applicat…EPSS 1.9%9.8CVE-2017-1000197Octobercms october vulnerabilityOctober CMS build 412 is vulnerable to file path modification in asset move functionality resulting in creating creating malicious files on the serve…EPSS 1.2%9.1CVE-2023-44382Octobercms october code injection vulnerabilityOctober is a Content Management System (CMS) and web platform to assist with development workflow. An authenticated backend user with the `editor.cms…EPSS 0.87%8.8CVE-2021-32649Octobercms october injection vulnerabilityOctober CMS is a self-hosted content management system (CMS) platform based on the Laravel PHP Framework. Prior to versions 1.0.473 and 1.1.6, an att…EPSS 1.3%8.8CVE-2021-32650Octobercms october injection vulnerabilityOctober CMS is a self-hosted content management system (CMS) platform based on the Laravel PHP Framework. Prior to versions 1.0.473 and 1.1.6, an att…EPSS 2.1%8.8CVE-2017-16941Octobercms october unrestricted file upload vulnerabilityOctober CMS through 1.0.428 does not prevent use of .htaccess in themes, which allows remote authenticated users to execute arbitrary PHP code by dow…EPSS 1.6%

Source: NIST National Vulnerability Database (record CVE-2021-3311), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.