# 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.

- **Severity:** High 7.5 (`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`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 30 Mar 2026
- **Updated:** 30 Mar 2026
- **Also known as:** GHSA-m62j-gwm9-7p8m

## 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.

Weakness: CWE-95 (Improper Neutralization of Directives in Dynamically Evaluated Code), CWE-94 (Improper Control of Generation of Code)

## Which versions are affected by CVE-2026-28505?

It affects 1 product.


Products: 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.

## 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](https://insights.sbomify.com/CVE-2025-58762/): Tautulli vulnerable to Authenticated Remote Code Execution via write primitive and `Script` notification agent (critical 9.1)
- [CVE-2026-31831](https://insights.sbomify.com/CVE-2026-31831/): Tautulli: Unauthenticated Path Traversal in `/newsletter/image/images` endpoint (high 8.7)
- [CVE-2025-58760](https://insights.sbomify.com/CVE-2025-58760/): Tautulli vulnerable to Unauthenticated Path Traversal in `/image` endpoint (high 8.6)
- [CVE-2025-58761](https://insights.sbomify.com/CVE-2025-58761/): Tautulli vulnerable to Unauthenticated Path Traversal in `real_pms_image_proxy` (high 8.6)
- [CVE-2025-58763](https://insights.sbomify.com/CVE-2025-58763/): Tautulli vulnerable to Authenticated Remote Code Execution via Command Injection (high 8.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-28505 and fix it if it is affected.

What it is: 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.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-28505 exists.

Affected product: Tautulli. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-28505/ (Markdown: https://insights.sbomify.com/CVE-2026-28505/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-28505
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-28505
- OSV: https://osv.dev/vulnerability/CVE-2026-28505

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-28505/
Summaries are generated and may contain mistakes; the official description above is the record.