Which products and versions are affected by CVE-2021-26599?

Affected: Impresscms; impresscms/impresscms (composer). The full list is in the CVE brief.

Is CVE-2021-26599 being exploited in the wild?

It is not listed in any known-exploited vulnerabilities catalog.

Is CVE-2021-26599 in the CISA KEV catalog?

No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.

Is there a public exploit for CVE-2021-26599?

Public exploit code is available.

Is there a fix for CVE-2021-26599?

Fixed versions are available, including Impresscms 1.4.4, impresscms/impresscms 1.4.3.

How urgently should CVE-2021-26599 be patched?

Brandefense priority: patch immediately, because public exploit code exists for a high-severity flaw.

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WatchlistCritical

CVE-2021-26599Impresscms SQL Injection

SQL Injection in ImpressCMS

Published Mar 29, 2022 · Updated Jul 9, 2026 · Also known as GHSA-jc4v-vvg6-xg78

Key Facts

Patch immediately

CVE-2021-26599 is a critical-severity vulnerability (CVSS 9.8 v3.1) affecting Impresscms, impresscms/impresscms (composer).
It is not listed in any known-exploited vulnerabilities catalog. Public exploit code is available.
EPSS estimates a 21% probability of exploitation in the next 30 days.
Fixed versions are available, including Impresscms 1.4.4, impresscms/impresscms 1.4.3.
Brandefense priority: patch immediately, because public exploit code exists for a high-severity flaw.

Scores

CVSS v3.1

9.8

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

EPSS (30-day exploit likelihood)

21%

Higher than 97.5% of all scored CVEs

Exploit maturity

Proof of concept

ATLAS score

47/100

Publication score, see How it works

Exploitation Verdict

KEV listed

Not listed

Federal due date

None

No federal due date

Ransomware use

Not reported

Attributed actors

None named

Exploit & Defence Guidance

Exploit maturity

Proof of concept

Public exploit code

Proof-of-concept links

In-the-wild evidence

Reports of active use

Advisories And Exploit References

advisoryhttps://nvd.nist.gov/vuln/detail/CVE-2021-26599
advisoryGHSA advisory
advisoryhttps://github.com/ImpressCMS/impresscms/releases/tag/v1.4.3
advisoryhttps://hackerone.com/reports/1081145

Description

ImpressCMS before 1.4.3 allows include/findusers.php groups SQL Injection.

Affected Products

2 affected entries in total

Product	Affected versions	Fixed in
ImpresscmsImpresscms	See advisory	1.4.4
impresscms/impresscmscomposer	See advisory	1.4.3

Patched Releases

Impresscms

1.4.4

impresscms/impresscms

1.4.3

Timeline

Publicly disclosed
Mar 29, 2022
Last updated
Jul 9, 2026

Weakness Type

CWE-89 Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection')

References

advisorynvd.nist.gov · CVE-2021-26599
advisoryGHSA advisory
advisorygithub.com · v1.4.3
advisoryhackerone.com · 1081145
exploitkarmainsecurity.com · KIS-2022-04

4 more references in the full CVE brief

FAQ

Common Questions.

ImpressCMS before 1.4.3 allows include/findusers.php groups SQL Injection.
Affected: Impresscms; impresscms/impresscms (composer). The full list is in the CVE brief.
It is not listed in any known-exploited vulnerabilities catalog.
No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.
Public exploit code is available.
Fixed versions are available, including Impresscms 1.4.4, impresscms/impresscms 1.4.3.
Brandefense priority: patch immediately, because public exploit code exists for a high-severity flaw.

Is CVE-2021-26599 On Your Attack Surface?

Brandefense matches it against the products discovered on your perimeter and opens a finding the day a CVE like this is listed.