StudioCMS: IDOR — Arbitrary API Token Revocation Leading to Denial of Service

published 2026-03-10 8 mo ago modified 2026-06-17 4 mo ago also GHSA-8rgj-vrfr-6hqr , EUVD-2026-10557

cvss: 7.1; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.5%; EPSS 0.5% chance of exploitation in 30 days, percentile 44%
public exploits: 0; none known

StudioCMS is a server-side-rendered, Astro native, headless content management system. Prior to 0.4.0, the DELETE /studiocms_api/dashboard/api-tokens endpoint allows any authenticated user with editor privileges or above to revoke API tokens belonging to any other user, including admin and owner accounts. The handler accepts tokenID and userID directly from the request payload without verifying token ownership, caller identity, or role hierarchy. This enables targeted denial of service against critical integrations and automations. This vulnerability is fixed in 0.4.0.

Patch / fix

fixed in 2 links 2

npm studiocms 0.4.0
studiocms studiocms 0.4.0

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 8 mo ago (2026-03-10)

Exploit prediction

0.53% chance of exploitation in the next 30 days, higher than 44% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

github.com https://github.com/withstudiocms/studiocms/security/advisories/GHSA-8rgj-vrfr-6hqr referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	3.1	7.1	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H
GitHub	3.1	7.1	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H

Affected packages

ecosystem	package	affected	fixed in
npm	studiocms	<0.4.0	0.4.0

Affected products

withstudiocms studiocms

Classification

Weakness

CWE-639 Authorization Bypass Through User-Controlled Key
CWE-863 Incorrect Authorization

References

github.com /withstudiocms/studiocms/commit/9eec9c3b45523b635cfe16d55aa55afabacbebe3
web, patch
github.com /withstudiocms/studiocms/security/advisories/GHSA-8rgj-vrfr-6hqr
web, exploit, vendor-advisory
github.com /withstudiocms/studiocms/releases/tag/studiocms@0.4.0
web, product
nvd.nist.gov /vuln/detail/CVE-2026-30945
advisory
github.com /withstudiocms/studiocms
package

Sources

Fencer Vulns 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.

Summary