CVE-2026-91142
LowCVSS 3.6Exploitation Probability (EPSS)
Low risk1th percentile - higher than 1% of all known CVEs
Summary
A vulnerability in Cockpit on ILP32 builds involves an integer overflow in the `do_lastlog()` function, specifically in offset calculation for lastlog entries. A low-privileged user with a specially provisioned large UID can cause the offset to wrap, allowing unauthorized reads and writes to other users' lastlog records, potentially disclosing or altering login information.
Risk Assessment
Attackers can access or modify other users' login records, leading to confidentiality and integrity breaches and compromising activity tracking.
Recommendation
Upgrade Cockpit to a patched version or restrict access to relevant system functions. Also ensure physical security for ILP32 systems.
Other vulnerabilities in Cockpit
See all- CVE-2026-4631Critical
Cockpit's remote login feature passes user-supplied hostnames and usernames from the web interface to the SSH client without validation. 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.
- CVE-2026-91149High
A vulnerability in Cockpit allows an unauthenticated remote attacker to initiate and sustain numerous simultaneous connections to the cockpit-tls service, forcing it to create an unbounded number of threads and consume system resources such as memory and file descriptors. The result is a denial of service (DoS).
- CVE-2026-4802High
A flaw was found in Cockpit that allows a remote attacker to execute arbitrary commands on the host by exploiting unsanitized user-controlled parameters in the system logs UI. An attacker can inject shell metacharacters and command substitutions, leading to arbitrary shell command execution on the affected system.
- CVE-2026-38993Medium
Directory traversal vulnerability in the Buckets component of Cockpit 2.13.5 and earlier. Allows authenticated attackers to write files to arbitrary locations within the uploads directory or overwrite assets with malicious versions.
Original NVD description (English source)
A flaw was found in Cockpit. An integer overflow vulnerability in the `do_lastlog()` function, specifically in the offset calculation for `lastlog` entries on ILP32 (Integer, Long, Pointer 32-bit) builds, can be exploited. A low-privileged authenticated user with a specially provisioned large User ID (UID) can cause the computed offset to wrap around. This allows the user to perform unauthorized reads and writes to other users' `lastlog` records, potentially disclosing or altering sensitive login accounting information.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS