# CVE-2026-29091: Locutus: Remote Code Execution (RCE) in locutus call_user_func_array due to Code Injection

> Attackers can execute arbitrary JavaScript code via the call_user_func_array function in the Locutus library due to insecure eval usage.

- **Severity:** High 8.1 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 6 Mar 2026
- **Updated:** 15 Jul 2026
- **Also known as:** GHSA-fp25-p6mj-qqg6

## What is CVE-2026-29091?

CVE-2026-29091 is a high-severity code injection vulnerability in locutusjs locutus, published on 6 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Locutus brings stdlibs of other programming languages to JavaScript for educational purposes. Prior to version 3.0.0, a remote code execution (RCE) flaw was discovered in the locutus project, specifically within the call_user_func_array function implementation. The vulnerability allows an attacker to inject arbitrary JavaScript code into the application's runtime environment. This issue stems from an insecure implementation of the call_user_func_array function (and its wrapper call_user_func), which fails to properly validate all components of a callback array before passing them to eval(). This issue has been patched in version 3.0.0.

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

## Which versions are affected by CVE-2026-29091?

2 open source packages ship an affected version, including locutus. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `locutus` | npm | All versions | 3.0.0 |
| `locutus` | npm | All versions | 3.0.0 |

Products: Locutus Locutus.

## How do I fix CVE-2026-29091?

Upgrade locutus to 3.0.0 or later.

## Is CVE-2026-29091 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-29091 exists.

## Other vulnerabilities in locutusjs locutus

- [CVE-2026-32304](https://insights.sbomify.com/CVE-2026-32304/): Locutus: RCE via unsanitized input in create_function() (critical 9.8)
- [CVE-2020-7719](https://insights.sbomify.com/CVE-2020-7719/): Prototype Pollution (critical 9.8)
- [CVE-2026-25521](https://insights.sbomify.com/CVE-2026-25521/): Locutus is vulnerable to Prototype Pollution (critical 9.4)
- [CVE-2026-33993](https://insights.sbomify.com/CVE-2026-33993/): Locutus has Prototype Pollution via __proto__ Key Injection in unserialize() (medium 6.9)
- [CVE-2026-33994](https://insights.sbomify.com/CVE-2026-33994/): Locutus Prototype Pollution due to incomplete fix for CVE-2026-25521 (medium 6.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-29091 and fix it if it is affected.

What it is: CVE-2026-29091 is a high-severity code injection vulnerability in locutusjs locutus, published on 6 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-29091 exists.

Affected packages and fixed versions:
- locutus (npm): affected all versions; fixed in 3.0.0
- locutus (npm): affected all versions; fixed in 3.0.0

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-2026-29091/ (Markdown: https://insights.sbomify.com/CVE-2026-29091/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-29091
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-29091
- OSV: https://osv.dev/vulnerability/CVE-2026-29091

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-29091/
Summaries are generated and may contain mistakes; the official description above is the record.