CVE-2026-28505 Tautulli: RCE via eval() sandbox bypass using lambda nested scope to escape co_names whitelist check
Attackers can execute arbitrary code by bypassing the eval sandbox in Tautulli notification templates using nested lambda scopes.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-28505?
CVE-2026-28505 is a high-severity code injection vulnerability in Tautulli, published on 30 Mar 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Official description
Tautulli is a Python based monitoring and tracking tool for Plex Media Server. Prior to version 2.17.0, the str_eval() function in notification_handler.py implements a sandboxed eval() for notification text templates. The sandbox attempts to restrict callable names by inspecting code.co_names of the compiled code object. However, co_names only contains names from the outer code object. When a lambda expression is used, it creates a nested code object whose attribute accesses are stored in code.co_consts, NOT in code.co_names. The sandbox never inspects nested code objects. This issue has been patched in version 2.17.0.
Which versions are affected by CVE-2026-28505?
It affects 1 product.
Products include Tautulli Tautulli.
How do I fix CVE-2026-28505?
No fix has been published for CVE-2026-28505 yet. Limit exposure of the affected software until one is available.
Upgrade, and never evaluate templates, expressions or code built from user input. More about Code injection.
Is CVE-2026-28505 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-28505 exists.
Other vulnerabilities in Tautulli
- CVE-2025-58762 Tautulli vulnerable to Authenticated Remote Code Execution via write primitive and `Script` notification agent
- CVE-2026-31831 Tautulli: Unauthenticated Path Traversal in `/newsletter/image/images` endpoint
- CVE-2025-58760 Tautulli vulnerable to Unauthenticated Path Traversal in `/image` endpoint
- CVE-2025-58761 Tautulli vulnerable to Unauthenticated Path Traversal in `real_pms_image_proxy`
- CVE-2025-58763 Tautulli vulnerable to Authenticated Remote Code Execution via Command Injection
Sources
Also known as GHSA-m62j-gwm9-7p8m.