# 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.

- **Severity:** Medium 4.3 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 21 Aug 2026
- **Updated:** 24 Aug 2026
- **Also known as:** GHSA-prj9-97mp-mwh2, GO-2026-5552

## 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 (Improper Input Validation)

## Which versions are affected by CVE-2026-53541?

3 open source packages ship an affected version, including github.com/OliveTin/OliveTin.


| Package | Ecosystem | 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.

## Is CVE-2026-53541 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-53541 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-53541 and fix it if it is affected.

What it is: 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.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-53541 exists.

Affected packages and fixed versions:
- github.com/OliveTin/OliveTin (Go): affected all versions; fixed in 0.0.0-20260531214440-ebffd9f040f7
- github.com/OliveTin/OliveTin (Go): affected all versions; fixed in 0.0.0-20260531214440-ebffd9f040f7
- github.com/OliveTin/OliveTin (Go): affected all versions; fixed in 0.0.0-20260531214440-ebffd9f040f7

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-53541/ (Markdown: https://insights.sbomify.com/CVE-2026-53541/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-53541
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-53541
- OSV: https://osv.dev/vulnerability/CVE-2026-53541

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-53541/
Summaries are generated and may contain mistakes; the official description above is the record.