What’s Vulnerable › Vulnerabilities

CVE-2021-3311

• Severity: critical (CVSS 9.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 2.9% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2021-02-05 · updated 2026-06-17
• Weakness: CWE-613

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.

Affected products

• octobercms october: through 1.0.471

References

• https://anisiosantos.me/october-cms-token-reactivation
• https://github.com/octobercms/library/commit/642f597489e6f644d4bd9a0c267e864cabead024
• https://octobercms.com/forum/chan/announcements
• https://anisiosantos.me/october-cms-token-reactivation
• https://github.com/octobercms/library/commit/642f597489e6f644d4bd9a0c267e864cabead024
• https://octobercms.com/forum/chan/announcements

Get alerted when CVE-2021-3311 or the next vulnerability affects your stack