CVE-2026-4878
Published: April 10, 2026Last modified: April 23, 2026
Description
A flaw was found in libcap. A local unprivileged user can exploit a Time-of-check-to-time-of-use (TOCTOU) race condition in the `cap_set_file()` function. This allows an attacker with write access to a parent directory to redirect file capability updates to an attacker-controlled file. By doing so, capabilities can be injected into or stripped from unintended executables, leading to privilege escalation.
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score | 7 |
| Attack Vector | LOCAL |
| Attack complexity | HIGH |
| Privileges required | LOW |
| User interaction | NONE |
| Scope | UNCHANGED |
| Confidentiality | HIGH |
| Integrity impact | HIGH |
| Availability impact | HIGH |
| Vector | CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H |
Status
| Product | Release | Package | Status |
|---|---|---|---|
| Alpaquita Linux | 23 LTS | libcap | Fixed (2.66-r2) |
| 25 LTS | libcap | Fixed (2.78-r0) | |
| Stream | libcap | Fixed (2.78-r0) |
References
- http://www.openwall.com/lists/oss-security/2026/04/07/14
- http://www.openwall.com/lists/oss-security/2026/04/07/4
- http://www.openwall.com/lists/oss-security/2026/04/08/9
- http://www.openwall.com/lists/oss-security/2026/04/09/5
- http://www.openwall.com/lists/oss-security/2026/04/09/6
- https://access.redhat.com/errata/RHSA-2026:12423
- https://access.redhat.com/errata/RHSA-2026:12441
- https://access.redhat.com/errata/RHSA-2026:13285
- https://access.redhat.com/errata/RHSA-2026:14162
- https://access.redhat.com/errata/RHSA-2026:14937
- https://access.redhat.com/errata/RHSA-2026:19130
- https://access.redhat.com/errata/RHSA-2026:19346
- https://access.redhat.com/errata/RHSA-2026:19456
- https://access.redhat.com/errata/RHSA-2026:19458
- https://access.redhat.com/errata/RHSA-2026:7473
- https://access.redhat.com/security/cve/CVE-2026-4878
- https://bugzilla.redhat.com/show_bug.cgi?id=2447554
- https://bugzilla.redhat.com/show_bug.cgi?id=2451615