locutus call_user_func_array vulnerable to Remote Code Execution (RCE) due to Code Injection

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

8.1 · CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS

• CVE-2026-29091: 0.89% estimated exploitation activity in the next 30 days; percentile 59.43 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Details A Remote Code Execution (RCE) flaw was discovered in the locutus project (v2.0.39), specifically within the calluserfuncarray 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 calluserfuncarray function (and its wrapper calluserfunc), which fails to properly validate all components of a callback array before passing them to eval(). ------ Technical Details The vulnerability is in the calluserfuncarray function in src/php/funchand/calluserfuncarray.js, between lines 31 and 35 of version 2.0.39. This function mimics PHP's dynamic function call feature and accepts a callback argument, which can be a string (function name) or an array (class and method name). The developers applied a regular expression check (validJSFunctionNamePattern) to the first array element (the class identifier), but not to the second element (the method…

Published by the source

4 Mar 2026, 20:19 UTC

Last modified by the source

6 Mar 2026, 23:01 UTC

Source last checked

26 Oct 2026, 12:43 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-fp25-p6mj-qqg6

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-fp25-p6mj-qqg6

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# Patch Next advisory brief: CVE-2026-29091

Advisory: locutus call_user_func_array vulnerable to Remote Code Execution (RCE) due to Code Injection
IDs: CVE-2026-29091, GHSA-fp25-p6mj-qqg6
Record: https://patchnext.com/advisories/cve-2026-29091 (revision 2, source checked 26 Oct 2026, 12:43 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 8.1)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: locutus 3.0.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm locutus: affected <= 2.0.39; fixed in 3.0.0

## Suggested inspection (read-only)
- `npm ls locutus --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on locutus.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-fp25-p6mj-qqg6 (OSV record GHSA-fp25-p6mj-qqg6 lists affected ranges: npm locutus >=0 <3.0.0 (fixed))
- Verified: https://github.com/advisories/GHSA-fp25-p6mj-qqg6 (GitHub-reviewed advisory GHSA-fp25-p6mj-qqg6 lists affected ranges: npm locutus >=0 <=2.0.39)

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