Raw vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:XCVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.
Summary
CVE-2026-29002 is a high-severity Authorization Bypass Through User-Controlled Key (CWE-639) vulnerability in Couchcms Couchcms. Its CVSS base score is 8.6 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 36th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified map to AC-24 (Access Control Decisions) and AC-3 (Access Enforcement) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2026-29002, published on 2026-04-10, is a privilege escalation vulnerability in CouchCMS. The issue allows authenticated Admin-level users to create SuperAdmin accounts by tampering with the f_k_levels_list parameter in user creation requests. Specifically, attackers can modify the parameter value from 4 to 10 in the HTTP request body, bypassing authorization validation and circumventing restrictions on SuperAdmin account creation and privilege assignment. It carries a CVSS v3.1 base score of 7.2 (AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H) and is associated with CWE-639 (Authorization Bypass Through User-Controlled Key).
An authenticated Admin-level user (PR:H) can exploit this vulnerability remotely over the network (AV:N) with low attack complexity (AC:L) and no user interaction (UI:N). Successful exploitation enables the creation of a SuperAdmin account, granting full application control and resulting in high impacts to confidentiality, integrity, and availability (C:H/I:H/A:H).
Advisories and additional details are available in referenced sources, including the VulnCheck advisory at https://www.vulncheck.com/advisories/couchcms-privilege-escalation-via-f-k-levels-list-parameter, a GitHub gist at https://gist.github.com/thepiyushkumarshukla/477e2d2bbbe8cc3ec0d640c50f0cf9e1, and the CouchCMS website at https://www.couchcms.com/.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-21384
Vulnerability Data
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…
more
to bypass authorization validation and gain full application control, circumventing restrictions on SuperAdmin account creation and privilege assignment.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Enforcing approved authorizations on every access request structurally stops a user-controlled key from reaching another user's data.
Requiring explicit access-control decisions on each request blocks unauthorized key-driven access.
Least-privilege restrictions limit the scope of data reachable even if a key check is bypassed.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Enforcing authorization policy and least privilege directly blocks user-controlled key tampering that bypasses access checks.
Logical access controls prevent unauthorized data access that results from missing authorization checks on object references.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Access control policy directly requires enforcement of authorization rules that prevent unauthorized access via manipulated keys.
Managing access rights includes ensuring users can only access their own records and not bypass authorization by altering identifiers.
Privileged access rights control restricts what data each user may access, mitigating direct object reference attacks.
Secure development lifecycle includes authorization design but does not itself implement runtime access checks.
Application security requirements can mandate authorization controls, yet the control itself is a requirements statement rather than an implemented safeguard.
Secure coding practices reduce the likelihood of missing authorization checks but do not guarantee their presence at runtime.