NIST deprecates RSA-2048 from 2030. Find every one of them before attackers do.
🐘
🐘 Packagist
Not in CISA KEV
HIGH severity

CVE-2026-38991 — cockpit

HIGH

CVE-2026-38991 is a high-severity (CVSS 8.8) Unrestricted File Upload vulnerability in cockpit-hq/cockpit. A fix is available for cockpit-hq/cockpit — see the affected versions and patch details below.

Cockpit Vulnerable to Unrestricted Upload of File with Dangerous Type

Also known asGHSA-j2rx-4jg9-79mw
Published
Updated
Affected
1 pkg
Patched
1 / 1
Exploits
None indexed
Exploitation data as of Nov 7, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

Proof-of-concept exploit code exists

  • CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
  • A successful exploit gives an attacker total control of the affected component, not partial access.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-38991.

EPSS Exploitation Probability

via FIRST.org ↗
0.4%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs32th percentile — riskier than 32% of all scored CVEsHighest risk
0.00%0.35%0.69%1.04%0.0%0.4%May 26Sep 26Nov 26

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

1 pkg affected
🐘cockpit-hq/cockpit

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.

Description

Cockpit versions 2.13.5 and earlier are affected by a misconfiguration within the Bucket component _isFileTypeAllowed function where a specially crafted filename bypasses an extension filter. This allows an authenticated attacker to rename arbitrary files with the .php file extension enabling arbitrary code to be executed on the underlying server.

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
🐘Packagistcockpit-hq/cockpitall versions2.14.0composer require cockpit-hq/cockpit:^2.14.0

Detection & mitigation playbook

Open-source dependency

  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for cockpit-hq/cockpit, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

  2. Fix

    Update cockpit-hq/cockpit to 2.14.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-38991 is resolved across your whole dependency graph.

  3. Workarounds

    Treat uploaded files as untrusted until proven otherwise: validate the actual content type rather than the supplied extension, store uploads outside the web root on a volume mounted without execute permission, and rename them to server-generated identifiers so an attacker cannot choose the path a request will later resolve.

Frequently Asked Questions

Cockpit versions 2.13.5 and earlier are affected by a misconfiguration within the Bucket component _isFileTypeAllowed function where a specially crafted filename bypasses an extension filter. This allows an authenticated attacker to rename arbitrary files with the .php file extension enabling arbitrary code to be executed on the underlying server.
O3 Security · Impact-Aware SCA

Is CVE-2026-38991 in your dependencies?

Find it across Packagist, including transitive dependencies.

Scan my dependencies How O3 SCA works
CVE-2026-38991: cockpit RCE — Fixed in 2.14.0