Nuclio Shell Runtime Command Injection Leading to Privilege Escalation

Exploitation

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

CVSS 4.0

8.9 · CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P · score source

EPSS

• CVE-2026-29042: 2.59% estimated exploitation activity in the next 30 days; percentile 85.29 (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.

Summary This vulnerability exists in Nuclio's Shell Runtime component, allowing attackers with function invocation permissions to inject malicious commands via HTTP request headers, execute arbitrary code with root privileges in function containers, steal ServiceAccount Tokens with cluster-admin level permissions, and ultimately achieve complete control over the entire Kubernetes cluster. Recommended CWE classification: CWE-78 (OS Command Injection). Nuclio Shell Runtime processes the X-Nuclio-Arguments HTTP header without validation or escaping, directly concatenating user input into shell commands executed via sh -c. This allows arbitrary command injection, enabling attackers to read sensitive files (including ServiceAccount tokens) and access the Kubernetes API with cluster-level privileges. Details Vulnerability Description The Nuclio Shell Runtime component contains a critical command injection vulnerability in how it processes user-supplied arguments. When a function is invoked…

Published by the source

4 Mar 2026, 21:05 UTC

Last modified by the source

6 Mar 2026, 21:57 UTC

Source last checked

26 Oct 2026, 15:15 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-95fj-3w7g-4r27

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# Patch Next advisory brief: CVE-2026-29042

Advisory: Nuclio Shell Runtime Command Injection Leading to Privilege Escalation
IDs: CVE-2026-29042, GHSA-95fj-3w7g-4r27
Record: https://patchnext.com/advisories/cve-2026-29042 (revision 1, source checked 26 Oct 2026, 15:15 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 8.9)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/nuclio/nuclio 1.15.20. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/nuclio/nuclio: affected <= 1.15.9; fixed in 1.15.20

## Suggested inspection (read-only)
- Go github.com/nuclio/nuclio: check the installed version with your package manager.

## 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 github.com/nuclio/nuclio.
- 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://github.com/advisories/GHSA-95fj-3w7g-4r27 (GitHub-reviewed advisory GHSA-95fj-3w7g-4r27 lists affected ranges: Go github.com/nuclio/nuclio >=0 <=1.15.9)

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