Auth bypass in Couchcms
CVE-2026-29002
CouchCMS contains a privilege escalation vulnerability that allows authenticated Admin-level users to create SuperAdmin accounts by tampering with the f_k_levels_list parameter in user creation requests. Attackers can modify the parameter value from 4 to 10 in the HTTP request body to bypass authorization validation and gain full application control, circumventing restrictions on SuperAdmin account creation and privilege assignment.
Vulnerability class: IDOR (Insecure Direct Object Reference)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.2 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.007 (49.6th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 50th percentile — 49.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.007 · change: +0.002
Affected products
- Couchcms — versions 0
Weakness classification (CWE)
References
- gist.github.com/thepiyushkumarshukla/477e2d2bbbe8cc3ec0d640c50f0cf9e1 (Exploit, technical-description, Third Party Advisory, exploit)
- www.couchcms.com/ (Product, product)
- www.vulncheck.com/advisories/couchcms-privilege-escalation-via-f-k-levels-list-… (Third Party Advisory, third-party-advisory)
Frequently asked questions
- What is CVE-2026-29002?
- CVE-2026-29002 is a high-severity vulnerability in Couchcms, classified under Authorization Bypass Through User-Controlled Key. CVSS score: 7.2/10. Published 2026-04-10.
- How severe is CVE-2026-29002?
- High severity. CVSS v3 base score is 7.2 out of 10.