CVE-2026-53541 OliveTin has Unvalidated `ot_`-prefixed Arguments that Bypass Input Filtering
Attackers can inject arbitrary shell commands via unvalidated ot_-prefixed arguments in OliveTin, leading to remote code execution.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-53541?
CVE-2026-53541 is a medium-severity command injection vulnerability in OliveTin, published on 21 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official 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.
Weakness: CWE-20
Which versions are affected by CVE-2026-53541?
3 open source packages ship an affected version, including github.com/OliveTin/OliveTin.
| Package | Affected | Fixed in |
|---|---|---|
github.com/OliveTin/OliveTin Go | All versions | 0.0.0-20260531214440-ebffd9f040f7 |
github.com/OliveTin/OliveTin Go | All versions | 0.0.0-20260531214440-ebffd9f040f7 |
github.com/OliveTin/OliveTin Go | All versions | 0.0.0-20260531214440-ebffd9f040f7 |
How do I fix CVE-2026-53541?
Upgrade github.com/OliveTin/OliveTin to 0.0.0-20260531214440-ebffd9f040f7 or later.
Upgrade, and pass arguments to programs as a list instead of through a shell. More about Command injection.
Is CVE-2026-53541 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-53541 exists.
Sources
Also known as GHSA-prj9-97mp-mwh2, GO-2026-5552.