What is CVE-2026-28281?

CVE-2026-28281 is a high-severity vulnerability in Instantcms, classified under Cross-Site Request Forgery (CSRF). CVSS score: 7.1/10. Published 2026-03-10.

How severe is CVE-2026-28281?

High severity. CVSS v3 base score is 7.1 out of 10.

CSRF in Instantcms

CVE-2026-28281

InstantCMS is a free and open source content management system. Prior to 2.18.1, InstantCMS does not validate CSRF tokens, which allows attackers grant moderator privileges to users, execute scheduled tasks, move posts to trash, and accept friend requests on behalf of the user. This vulnerability is fixed in 2.18.1.

Vulnerability class: CSRF (Cross-Site Request Forgery)

Published 2026-03-10 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.1 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:H/A:N.

EPSS exploit prediction

EPSS: 0.002 (5.1th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 5th percentile — 5.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.001 · newest: 0.002 · change: +0.000

Affected products

Instantcms
Instantsoft Icms2 — versions < 2.18.1

Weakness classification (CWE)

CWE-352 — Cross-Site Request Forgery (CSRF)

References

github.com/instantsoft/icms2/security/advisories/GHSA-pp43-262q-h73m (Exploit, Mitigation, Vendor Advisory)

Frequently asked questions

What is CVE-2026-28281?: CVE-2026-28281 is a high-severity vulnerability in Instantcms, classified under Cross-Site Request Forgery (CSRF). CVSS score: 7.1/10. Published 2026-03-10.
How severe is CVE-2026-28281?: High severity. CVSS v3 base score is 7.1 out of 10.