CVE-2026-4878: Time-of-check Time-of-use (TOCTOU) Race Condition in Red Hat Red Hat Enterprise Linux 10
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.
AI Analysis
Technical Summary
The libcap library, used for managing POSIX.1e capabilities, contains a TOCTOU race condition in the cap_set_file() function that allows privilege escalation (CVE-2026-4878). This race condition arises when the state of a file is checked and then used without proper synchronization, enabling an attacker to exploit the timing window to escalate privileges. Red Hat has issued security advisories RHSA-2026:12423 and RHSA-2026:12441 providing updated libcap packages that fix this vulnerability for Red Hat Enterprise Linux versions 8, 9, and 10 on multiple architectures including x86_64, s390x, ppc64le, and aarch64.
Potential Impact
Successful exploitation of this vulnerability could allow a local attacker to escalate privileges on affected systems by exploiting the race condition in cap_set_file(). This could lead to unauthorized access or control over system resources that require elevated privileges.
Mitigation Recommendations
Red Hat has released official security updates that fix this vulnerability. Users should apply the libcap package updates provided in Red Hat Enterprise Linux 8, 9, and 10 as detailed in advisories RHSA-2026:12423 and RHSA-2026:12441. Refer to https://access.redhat.com/articles/11258 for update instructions. No additional mitigation steps are required beyond applying the official patches.
CVE-2026-4878: Time-of-check Time-of-use (TOCTOU) Race Condition in Red Hat Red Hat Enterprise Linux 10
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.
CVSS v3.1
Score 6.7medium
Affected software
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The libcap library, used for managing POSIX.1e capabilities, contains a TOCTOU race condition in the cap_set_file() function that allows privilege escalation (CVE-2026-4878). This race condition arises when the state of a file is checked and then used without proper synchronization, enabling an attacker to exploit the timing window to escalate privileges. Red Hat has issued security advisories RHSA-2026:12423 and RHSA-2026:12441 providing updated libcap packages that fix this vulnerability for Red Hat Enterprise Linux versions 8, 9, and 10 on multiple architectures including x86_64, s390x, ppc64le, and aarch64.
Potential Impact
Successful exploitation of this vulnerability could allow a local attacker to escalate privileges on affected systems by exploiting the race condition in cap_set_file(). This could lead to unauthorized access or control over system resources that require elevated privileges.
Mitigation Recommendations
Red Hat has released official security updates that fix this vulnerability. Users should apply the libcap package updates provided in Red Hat Enterprise Linux 8, 9, and 10 as detailed in advisories RHSA-2026:12423 and RHSA-2026:12441. Refer to https://access.redhat.com/articles/11258 for update instructions. No additional mitigation steps are required beyond applying the official patches.
Technical Details
- Gcve Source
- db.gcve.eu
- Csaf Category
- csaf_security_advisory
- Csaf Version
- 2.0
- Publisher
- Red Hat Product Security
- Advisory Id
- RHSA-2026:20595
- Cve Count
- 1
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 6a16097de29bf47b50649db2
Added to database: 05/26/2026, 20:58:37 UTC
Last enriched: 08/16/2026, 16:27:29 UTC
Last updated: 09/13/2026, 22:01:34 UTC
Views: 133
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