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)

EPSS: 0.001 (2.8th percentile) — read the EPSS interpretation.

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.

Affected products

Weakness classification (CWE)

References

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.