What’s Vulnerable › Vulnerabilities

CVE-2026-53541: OliveTin has Unvalidated `ot_`-prefixed Arguments that Bypass Input Filtering

• Severity: medium (CVSS 4.3 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-08-21 · updated 2026-10-14
• Weakness: CWE-20

Description

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.

Affected products

• OliveTin: through 2025.03.07

References

• https://github.com/OliveTin/OliveTin/commit/ebffd9f040f791208aee1db2e5a8aecd1e3e603d
• https://github.com/OliveTin/OliveTin/security/advisories/GHSA-prj9-97mp-mwh2
• https://github.com/OliveTin/OliveTin/security/advisories/GHSA-prj9-97mp-mwh2

Get alerted when CVE-2026-53541 or the next vulnerability affects your stack