Is CVE-2026-38991 in the CISA KEV catalog?

No. CVE-2026-38991 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2026-38991?

CVE-2026-38991 has a CVSS v3 base score of 8.8 (HIGH).

What is the EPSS score for CVE-2026-38991?

CVE-2026-38991 has an EPSS score of 0.38% (29th percentile), estimating the probability of exploitation in the next 30 days.

CVE & CISA-KEV Catalog

CVE-2026-38991

HIGH

8.8

CVSS v3

NVD

Description

Cockpit 2.13.5 and earlier is 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.

CWE-434Unrestricted File Upload

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredLow

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityHigh

IntegrityHigh

AvailabilityHigh

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

Exploit Intelligence

0.38%probability of exploitation in 30 days

29thpercentile

Low risk: more likely to be exploited than 29% of all known CVEs.

References

Find and fix vulnerabilities across your fleet

TridentStack Control continuously scans your Windows, macOS, and Linux fleet for known vulnerabilities, prioritizes them by severity and active exploitation, and patches them automatically.

Start free

This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-04-29.