# CVE-2026-28789: OliveTin: Unauthenticated DoS via concurrent map writes in OAuth2 state handling

> Unauthenticated attackers can crash OliveTin by triggering a race condition in OAuth2 state handling, requiring OAuth2 to be enabled.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 5 Mar 2026
- **Updated:** 6 Mar 2026
- **Also known as:** GHSA-45m3-398w-m2m9, GO-2026-4586

## What is CVE-2026-28789?

CVE-2026-28789 is a high-severity vulnerability in OliveTin, published on 5 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

OliveTin gives access to predefined shell commands from a web interface. Prior to version 3000.10.3, an unauthenticated denial-of-service vulnerability exists in OliveTin’s OAuth2 login flow. Concurrent requests to /oauth/login can trigger unsynchronized access to a shared registeredStates map, causing a Go runtime panic (fatal error: concurrent map writes) and process termination. This allows remote attackers to crash the service when OAuth2 is enabled. This issue has been patched in version 3000.10.3.

Weakness: CWE-662 (Improper Synchronization), CWE-400 (Uncontrolled Resource Consumption), CWE-362 (Concurrent Execution using Shared Resource with Improper Synchronization)

## Which versions are affected by CVE-2026-28789?

3 open source packages ship an affected version, including github.com/OliveTin/OliveTin. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `github.com/OliveTin/OliveTin` | Go | All versions | None |
| `github.com/OliveTin/OliveTin` | Go | All versions | 0.0.0-20260301235225-f044d90d5525c |
| `github.com/OliveTin/OliveTin` | Go | All versions | 0.0.0-20260301235225-f044d90d5525c |

Products: Olivetin Olivetin.

## How do I fix CVE-2026-28789?

Upgrade github.com/OliveTin/OliveTin to 0.0.0-20260301235225-f044d90d5525c or later.

## Is CVE-2026-28789 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-28789 exists.

## Other vulnerabilities in OliveTin

- [CVE-2026-27626](https://insights.sbomify.com/CVE-2026-27626/): OliveTin: OS Command Injection via `password` argument type and webhook JSON extraction bypasses shell safety checks (critical 10.0)
- [CVE-2026-30223](https://insights.sbomify.com/CVE-2026-30223/): OliveTin: JWT Audience Validation Bypass in Local Key and HMAC Modes (high 8.8)
- [CVE-2026-31817](https://insights.sbomify.com/CVE-2026-31817/): OliveTin's unsafe parsing of UniqueTrackingId can be used to write files (high 8.5)
- [CVE-2026-28342](https://insights.sbomify.com/CVE-2026-28342/): OliveTin: Unauthenticated Denial of Service via Memory Exhaustion in PasswordHash API Endpoint (high 7.5)
- [CVE-2026-28790](https://insights.sbomify.com/CVE-2026-28790/): OliveTin: Unauthenticated Action Termination via KillAction When Guests Must Login (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-28789 and fix it if it is affected.

What it is: CVE-2026-28789 is a high-severity vulnerability in OliveTin, published on 5 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-28789 exists.

Affected packages and fixed versions:
- github.com/OliveTin/OliveTin (Go): affected all versions; no fix listed
- github.com/OliveTin/OliveTin (Go): affected all versions; fixed in 0.0.0-20260301235225-f044d90d5525c
- github.com/OliveTin/OliveTin (Go): affected all versions; fixed in 0.0.0-20260301235225-f044d90d5525c

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-2026-28789/ (Markdown: https://insights.sbomify.com/CVE-2026-28789/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-28789
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-28789
- OSV: https://osv.dev/vulnerability/CVE-2026-28789

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-28789/
Summaries are generated and may contain mistakes; the official description above is the record.