Which versions of Python are affected by CVE-2026-28505?

Tautulli versions before 2.17.0 contain a remote code execution vulnerability in notification template processing that allows authenticated administrators to execute arbitrary Python code by…. A patch is available.

How to fix or mitigate CVE-2026-28505?

Within 24 hours: Inventory all Tautulli deployments and identify instances running versions prior to 2.17.0. Within 7 days: Upgrade Tautulli to version 2.17.0 or later on all affected systems; verify notification template functionality post-upgrade. Within 30 days: Conduct access review of Tautulli administrative accounts and implement principle of least privilege for admin role assignments.

Python CVE-2026-28505

Q: What is the CVSS score of CVE-2026-28505?

CVE-2026-28505 has a CVSS 4.0 base score of 7.5 (High). 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X. EPSS exploitation probability: 0.0%.

EUVD-2026-17184 HIGH

Code Injection (CWE-94)

2026-03-30 GitHub_M

Python Code Injection RCE

7.5

CVSS 4.0 · GitHub Advisory

Severity by source

GitHub Advisory PRIMARY

7.5 HIGH

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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Primary rating from GitHub Advisory · only source for this CVE.

CVSS VectorGitHub Advisory

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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Attack Vector

Network

Attack Complexity

High

Privileges Required

High

User Interaction

None

Scope

Lifecycle Timeline

Analysis Updated

Apr 16, 2026 - 06:11 EUVD-patch-fix

executive_summary

Re-analysis Queued

Apr 16, 2026 - 05:29 backfill_euvd_patch

patch_released

Patch available

Apr 16, 2026 - 05:29 EUVD

2.17.0

EUVD ID Assigned

Mar 30, 2026 - 19:45 euvd

EUVD-2026-17184

Analysis Generated

Mar 30, 2026 - 19:45 vuln.today

CVE Published

Mar 30, 2026 - 19:41 nvd

HIGH 7.5

DescriptionGitHub Advisory

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.

AnalysisAI

Remote code execution in Tautulli (Python-based Plex Media Server monitoring tool) versions prior to 2.17.0 allows authenticated administrators to bypass sandbox restrictions in notification templates via lambda expressions, enabling arbitrary Python code execution. The vulnerability exploits a flaw in the str_eval() sandbox implementation that only inspects outer code object names (co_names) while nested lambda code objects store attribute accesses in co_consts, evading security checks. CVSS 7.5 with high attack complexity and high privilege requirement (PR:H) indicates limited real-world risk scope, with no public exploit identified at time of analysis.

Technical ContextAI

The vulnerability resides in Tautulli's notification_handler.py module, specifically within the str_eval() function that implements a sandboxed eval() mechanism for processing notification text templates. The sandbox's security model relies on whitelisting callable names by examining the code.co_names attribute of compiled Python code objects. However, this approach exhibits a fundamental design flaw in handling nested code structures: when lambda expressions are compiled, Python creates separate nested code objects with their own attribute access patterns stored in code.co_consts rather than the parent's co_names. The sandbox implementation fails to recursively inspect these nested code objects, creating a bypass vector. This is classified as CWE-94 (Improper Control of Generation of Code / Code Injection), representing a classic sandbox escape vulnerability where insufficient input validation allows execution of arbitrary code within a supposedly restricted environment. The affected product is identified as cpe:2.3:a:tautulli:tautulli:*:*:*:*:*:*:*:*, specifically targeting all versions before 2.17.0.

RemediationAI

Upgrade immediately to Tautulli version 2.17.0 or later, which contains comprehensive patching of the str_eval() sandbox escape vulnerability. The patched release is available at https://github.com/Tautulli/Tautulli/releases/tag/v2.17.0 with full release notes and installation instructions. The fix implements recursive inspection of nested code objects within the sandbox validation logic, closing the lambda expression bypass vector. Organizations unable to immediately upgrade should implement compensatory controls including restricting administrative access to Tautulli interfaces to trusted network segments only, implementing multi-factor authentication for administrator accounts, auditing existing notification templates for suspicious lambda expressions or complex Python constructs, and monitoring Tautulli logs for unusual notification processing activity. No workaround disables the vulnerable functionality while maintaining notification capabilities, making version upgrade the only complete remediation path.