CVE-2026-28505

CRITICAL

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

Title source: cna
STIX 2.1

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.

Scores

CVSS v3 10.0
EPSS 0.0003
EPSS Percentile 7.4%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

CISA SSVC

Vulnrichment
Exploitation poc
Automatable no
Technical Impact total

Details

CWE
CWE-94 CWE-95
Status published
Products (2)
tautulli/tautulli < 2.17.0
Tautulli/Tautulli < 2.17.0
Published Mar 30, 2026
Tracked Since Mar 31, 2026