---
id: CVE-2026-91142
title: A flaw was found in Cockpit
summary: >-
  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-privileg…
severity: low
cvss: 3.6
cvssVector: 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:N'
cwe:
  - CWE-787
vendor: Red Hat
product: cockpit
affected:
  - cockpit (all versions)
  - cockpit
  - cockpit
  - cockpit (all versions)
  - devspaces/udi-base-rhel10
  - devspaces/udi-base-rhel9
  - devspaces/udi-rhel9
published: '2026-09-18'
updated: '2026-09-18'
sourceUpdated: '2026-09-18T19:06:08.407'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-91142'
references:
  - url: 'https://access.redhat.com/security/cve/CVE-2026-91142'
    label: secalert@redhat.com
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2479459'
    label: secalert@redhat.com
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-91142.json
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-91142'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-91142'
tags:
  - nvd
  - cve.org
  - csaf
  - vex
  - red-hat
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-09-18T17:09:31.218316Z'
ingestedAt: '2026-09-18T16:45:41.403Z'
epss: 0.00125
epssPercentile: 0.01883
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Vendor advisories

- **Red Hat VEX** · Low · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat OpenShift Dev Spaces · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9 · updated 2026-09-21 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-91142.json)