CVE-2026-28789

OliveTin has unauthenticated DoS via concurrent map writes in OAuth2 state handling

• Vulnerability type: Race condition (CWE-362) leading to DoS.
  • Attacker requirements: network access only; no authentication required for exploit path.
  • Impacted deployments: OliveTin instances with OAuth2 enabled and reachable over network.
  • Security impact: remote unauthenticated attacker can repeatedly crash OliveTin, causing availability loss until restart/recovery.

poc_oauth2_state_map_race_dos.py

Multiple concurrent operations access a shared resource without proper synchronization, producing unpredictable results depending on timing. Typical impact: TOCTOU exploits, data corruption, or privilege escalation.

CVE-2026-28789 has a CVSS score of 7.5 (High). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (0.0.0-20260301235225-f044d90d5525c); upgrading removes the vulnerable code path.

Kodem intelligence

1. What is CVE-2026-28789? CVE-2026-28789 is a high-severity race condition vulnerability in github.com/OliveTin/OliveTin (go), affecting versions < 0.0.0-20260301235225-f044d90d5525c. It is fixed in 0.0.0-20260301235225-f044d90d5525c. Multiple concurrent operations access a shared resource without proper synchronization, producing unpredictable results depending on timing.
2. How severe is CVE-2026-28789? CVE-2026-28789 has a CVSS score of 7.5 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of github.com/OliveTin/OliveTin are affected by CVE-2026-28789? github.com/OliveTin/OliveTin (go) versions < 0.0.0-20260301235225-f044d90d5525c is affected.
4. Is there a fix for CVE-2026-28789? Yes. CVE-2026-28789 is fixed in 0.0.0-20260301235225-f044d90d5525c. Upgrade to this version or later.
5. Is CVE-2026-28789 exploitable, and should I be worried? Whether CVE-2026-28789 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2026-28789 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2026-28789? Upgrade github.com/OliveTin/OliveTin to 0.0.0-20260301235225-f044d90d5525c or later.