CVE-2026-4631

CVE-2026-4631 is a critical-severity vulnerability with a CVSS 3.x base score of 9.8. Its EPSS exploit-prediction score of 14% places it in the 96th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-78.

Key facts

Description

Cockpit's remote login feature passes user-supplied hostnames and usernames from the web interface to the SSH client without validation or sanitization. An attacker with network access to the Cockpit web service can craft a single HTTP request to the login endpoint that injects malicious SSH options or shell commands, achieving code execution on the Cockpit host without valid credentials. The injection occurs during the authentication flow before any credential verification takes place, meaning no login is required to exploit the vulnerability.

Frequently asked questions

What is CVE-2026-4631?
Cockpit's remote login feature passes user-supplied hostnames and usernames from the web interface to the SSH client without validation or sanitization. An attacker with network access to the Cockpit web service can craft a single HTTP request to the login endpoint that injects malicious SSH options or shell commands, achieving code execution on the Cockpit host without valid credentials. The injection occurs during the authentication flow before any credential verification takes place, meaning no login is required to exploit the vulnerability.
How severe is CVE-2026-4631?
CVE-2026-4631 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-4631 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 14% (96th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-4631?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
Does CVE-2026-4631 have an EU (EUVD) identifier?
Yes. CVE-2026-4631 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-19814.
When was CVE-2026-4631 published?
CVE-2026-4631 was published on 2026-04-07 and last updated on 2026-06-27.

References

Other CWE-78 (OS Command Injection) vulnerabilities

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