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CVE-2021-26600

Type Confusion in ImpressCMS

9.8 CriticalFix available

CVE-2021-26600 is a critical vulnerability (CVSS 9.8) in Impresscms, published March 28, 2022. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 5.63%, the 93rd percentile. Fixed in impresscms/impresscms 1.4.3.

What does this mean?
Severity
9.8 CriticalCVSS 3.1, NVD
Exploit chance
5.63%EPSS, 93rd percentile
Exploitation
None knownNot on CISA’s or ENISA’s lists
Fixed in
1.4.3impresscms/impresscms

Description

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

Attack profile

How easy it is to exploit

Attack vector
Network
Complexity
Low
Privileges needed
None
User interaction
None

What an attacker can affect

Confidentiality
High
Integrity
High
Availability
High

Exploit likelihood

5.63%Up 4.7 points since Mar 28, 2022
90%50%10%1%

Affected products

Affected packages

Affected packages
PackageAffectedFixed
impresscms/impresscms
Packagist
before 1.4.3
1.4.3

What each source reports

NVD Score used9.8

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

Record
CVE-2021-26600
CVSS 3.1
9.8 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS 2.0
7.5 HighAV:N/AC:L/Au:N/C:P/I:P/A:P
Weakness
CWE-843
Updated
2026-11-02
CVE ListNo score

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

Record
CVE-2021-26600
Updated
2026-11-02
EUVDEUVD-2022-1471No score

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

Record
EUVD-2022-1471
Updated
2026-11-03
GitHub AdvisoriesGHSA-m8xh-cqc2-5q6f9.8

Type Confusion in ImpressCMS

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

Record
GHSA-m8xh-cqc2-5q6f
CVSS 3.1
9.8 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness
CWE-843
Updated
2026-11-02
OSV9.8

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

Record
CVE-2021-26600
CVSS 3.1
9.8 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Updated
2026-11-02
OSVGHSA-m8xh-cqc2-5q6f9.8

Type Confusion in ImpressCMS

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

Record
GHSA-m8xh-cqc2-5q6f
CVSS 3.1
9.8 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness
CWE-843
Updated
2026-11-02

History

History
RecordedChangedSources
aliasesEUVD
first indexedCVE List, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

References

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