Improper input validation in Olivetin
CVE-2026-53541
OliveTin gives access to predefined shell commands from a web interface. The `filterToDefinedArgumentsOnly` function in the executor is intended to discard any arguments not explicitly defined in the action's configuration. However, prior to commit ebffd9f040f791208aee1db2e5a8aecd1e3e603d, a special case allows any argument whose name starts with `ot_` to bypass this filter. While two system arguments (`ot_executionTrackingId` and `ot_username`) are injected by OliveTin and overridden, all other `ot_`-prefixed arguments supplied by the user pass through unmodified. These bypassed arguments are not type-checked — the validation loop only iterates over the action's defined arguments, so `ot_`-prefixed arguments skip all type safety checks entirely; set as environment variables — via `buildEnv()`, with completely unvalidated values, and passed to the executed command; and included in the template context — available as `.Arguments.ot_*` in template rendering. Commit ebffd9f040f791208aee1db2e5a8aecd1e3e603d contains a patch.
Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)
CVSS v3 metric
CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N.
Affected products
- Olivetin — versions <= 2025.03.07
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM)
- security-advisories@github.com (x_refsource_MISC)
Frequently asked questions
- What is CVE-2026-53541?
- CVE-2026-53541 is a medium-severity vulnerability in Olivetin, classified under Improper Input Validation. CVSS score: 4.3/10. Published 2026-08-21.
- How severe is CVE-2026-53541?
- Medium severity. CVSS v3 base score is 4.3 out of 10.