CVE intelligence and bounded remediation
CVE-2026-4878 — A flaw was found in libcap
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
- High
- CVSS
- 7 (3.1)
- Published
- 2026-04-09
- CISA KEV
- Not currently listed
- Ecosystem
- software/application
- Weaknesses
- CWE-367
Affected products
- libcap_project / libcap
- redhat / openshift_container_platform / 4.0
- redhat / enterprise_linux / 8.0
- redhat / enterprise_linux / 9.0
- redhat / enterprise_linux / 10.0
Matched remediation archetype
Race condition, TOCTOU, and lifecycle synchronization
This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.
Check exposure
- Map concurrent actors, shared state, lock boundaries, signals, callbacks, retries, and check-then-use sequences in the affected path.
- Determine whether untrusted users can influence timing, object names, filesystem state, or repeated state transitions.
- Identify clustered and multi-process behavior that repository-local tests may not represent.
Remediate safely
- Make the sensitive state transition atomic or protect it with a consistently ordered synchronization primitive.
- Perform authorization and invariant checks on the same authoritative object and transaction used for the operation.
- Use unique private resources, safe ownership transfer, and idempotent operations; add deterministic concurrency regression tests.
Authoritative sources
Complete CVE record and remediation plan
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