{"id":"CVE-2026-53541","aliases":["GHSA-prj9-97mp-mwh2","GO-2026-5552"],"url":"https://o3.security/vulnerability/CVE-2026-53541","summary":"OliveTin has Unvalidated `ot_`-prefixed Arguments that Bypass Input Filtering","details":"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.","published":"2026-08-21T22:51:52.752Z","modified":"2026-09-11T03:30:24.501876610Z","cvss":{"score":4.3,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N"},"epss":{"score":0.00275,"percentile":0.19879,"asOf":"2026-09-12"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Go","name":"github.com/OliveTin/OliveTin","fixedVersion":"0.0.0-20260531214440-ebffd9f040f7"}],"fix":{"url":"https://github.com/OliveTin/OliveTin/commit/ebffd9f040f791208aee1db2e5a8aecd1e3e603d","label":"OliveTin/OliveTin@ebffd9f"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53541.json"},{"type":"ADVISORY","url":"https://github.com/OliveTin/OliveTin/security/advisories/GHSA-prj9-97mp-mwh2"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-53541"},{"type":"FIX","url":"https://github.com/OliveTin/OliveTin/commit/ebffd9f040f791208aee1db2e5a8aecd1e3e603d"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-09-11T03:30:24.501876610Z"}}