CVE-2026-91142
Cockpit: integer overflow in `do_lastlog()` offset calculation can misaddress `lastlog` entries on ilp32 builds
Description
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.
INFO
Published Date :
Sept. 18, 2026, 5:17 p.m.
Last Modified :
Sept. 18, 2026, 7:06 p.m.
Remotely Exploit :
No
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-91142
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | LOW | 53f830b8-0a3f-465b-8143-3b8a9948e749 | ||||
| CVSS 3.1 | LOW | [email protected] |
Solution
- Validate User ID before offset calculation.
- Sanitize offset to prevent wrap-around.
- Apply patches for Cockpit.
- Update Cockpit to the latest version.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-91142.
| URL | Resource |
|---|---|
| https://access.redhat.com/security/cve/CVE-2026-91142 | |
| https://bugzilla.redhat.com/show_bug.cgi?id=2479459 |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-91142 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-91142
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-91142 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-91142 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Sep. 18, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-91142', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-09-18T17:09:31.218316Z'} -
New CVE Received by [email protected]
Sep. 18, 2026
Action Type Old Value New Value Added Description 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. Added CVSS V3.1 AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:N Added CWE CWE-787 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/91xxx/CVE-2026-91142.json">CVE-2026-91142</a> Added Reference https://access.redhat.com/security/cve/CVE-2026-91142 Added Reference https://bugzilla.redhat.com/show_bug.cgi?id=2479459