Skip to content
Fencer Intel
high 8.8

CVE-2026-88418 json

CMSimple 5.24 ships with CSRF protection disabled by default, which turns csrfProtection() into a no-op on every state-changing admin reque…

published last mo. modified last mo. also EUVD-2026-84857

cvss
8.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 17%
public exploits
0
none known

Summary

CMSimple 5.24 ships with CSRF protection disabled by default, which turns csrfProtection() into a no-op on every state-changing admin request, and it does not send the csrf_token hidden field in admin forms. Because administrator authentication is cookie-only and no CSRF token is enforced, an unauthenticated attacker can induce a logged-in administrator's browser to issue a forged content-save request with a text payload containing a scripting marker. The marker is stored verbatim into content/content.php; on every subsequent page view evaluate_cmsimple_scripting() (functions.php) executes the marker body with PHP eval() — for all visitors, including unauthenticated ones. This yields persistent remote code execution on the web server.

Is CVE-2026-88418 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

Check with Fencer

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
total
Assessed
last mo.

Exploit prediction

0.25% chance of exploitation in the next 30 days, higher than 17% of all scored CVEs (FIRST EPSS, 2026-11-11).

Exploits and checks

  • github.com https://github.com/15536818056/CVE/issues/5 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CISA ADP 3.1 8.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CNA 3.1 8.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Classification

Weakness
  • CWE-352 Cross-Site Request Forgery

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.