CVE-2026-28505 HIGH

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

Vendor Tautulli
Product Tautulli
Weakness CWE-94 · Code injection
Published March 30, 2026
Last update March 30, 2026

CVSS base score

7.5/10
Attack vector Network
Attack complexity High
Privileges required High
User interaction None
Confidentiality
Integrity

CVSS 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

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

March 30, 2026 CVE published
March 30, 2026 Record updated