Auth bypass in Spip Crayons Plugin
CVE-2026-104070
The Crayons plugin for SPIP before 3.5.0 contains a missing authorization vulnerability that allows unauthenticated attackers to modify arbitrary editable object fields by omitting the secu_ anti-forgery parameter in crayons_store.php, causing the authorization dispatcher to resolve an unconditionally-true handler instead of the proper modification check. Attackers can chain this flaw to write a malicious .html skeleton file, disclose sensitive configuration files containing the site secret, and forge a signed ajax context to execute the uploaded skeleton, achieving arbitrary PHP code execution as the web-server user.
Vulnerability class: Broken Access Control
Published .
CVSS v3 metric
CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
Weakness classification (CWE)
References
- blog.spip.net/Mises-a-jour-de-securite-critique-plugins-Crayons-et-Simplog.html (vendor-advisory, patch)
- plugins.spip.net/crayons.html (product)
- www.vulncheck.com/advisories/spip-crayons-plugin-authorization-bypass-rce (third-party-advisory)
Frequently asked questions
- What is CVE-2026-104070?
- CVE-2026-104070 is a critical-severity vulnerability in Spip Crayons Plugin, classified under Missing Authorization. CVSS score: 9.8/10. Published 2026-10-06.
- How severe is CVE-2026-104070?
- Critical severity. CVSS v3 base score is 9.8 out of 10.