CVE-2021-26600

Name: CVE-2021-26600
Creator: NVD / NIST
Published: 2022-03-28T01:15:06.927+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.8/10EPSS 5.54%

Last modified Jun 17, 2026

CVE-2021-26600 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. ImpressCMS before 1.4.3 has plugins/preloads/autologin.php type confusion with resultant Authentication Bypass (!= instead of !==).. EPSS estimates a 5.54% chance of exploitation in the next 30 days.

Description

ImpressCMS before 1.4.3 has plugins/preloads/autologin.php type confusion with resultant Authentication Bypass (!= instead of !==).

Metrics

CVSS 3.1

9.8/10

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

EPSS Probability

5.54%

91.8th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-843

Affected Software

Vendor	Product	Versions
Impresscms	Impresscms	< 1.4.3

References

http://karmainsecurity.com/KIS-2022-01Third Party Advisory
http://packetstormsecurity.com/files/166393/ImpressCMS-1.4.2-Authentication-Bypass.htmlExploit, Third Party Advisory, VDB Entry
http://seclists.org/fulldisclosure/2022/Mar/43Exploit, Mailing List, Third Party Advisory
https://hackerone.com/reports/1081986Exploit, Third Party Advisory
http://karmainsecurity.com/KIS-2022-01Third Party Advisory
http://packetstormsecurity.com/files/166393/ImpressCMS-1.4.2-Authentication-Bypass.htmlExploit, Third Party Advisory, VDB Entry
http://seclists.org/fulldisclosure/2022/Mar/43Exploit, Mailing List, Third Party Advisory
https://hackerone.com/reports/1081986Exploit, Third Party Advisory

Timeline

Published: Mar 28, 2022
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-26600?

ImpressCMS before 1.4.3 has plugins/preloads/autologin.php type confusion with resultant Authentication Bypass (!= instead of !==).

How severe is CVE-2021-26600?

CVE-2021-26600 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 5.54% probability of exploitation in the next 30 days.

How do I fix CVE-2021-26600?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-26600?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST