Review reviewHigh

CVE-2026-4878

Red Hat Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 10.0 Extended Update Support, Red Hat Enterprise Linux 8

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
7
EPSS
0.21%
10.8% percentile
CISA KEV
Not listed
Published
2026.04.10
PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV
Exploit probability0.21%
Technical severityCVSS 7

Vulnerability overview

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.

Affected product and versions

Product
Red Hat Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 10.0 Extended Update Support, Red Hat Enterprise Linux 8
Affected versions
4.0, 8.0, 9.0, 10.0
Fixed versions
No verified fixed-version field is available yet

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide
  1. 1
    Identify

    Confirm that Red Hat Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 10.0 Extended Update Support, Red Hat Enterprise Linux 8 and an affected version are present.

  2. 2
    Prioritize

    Combine exploitation signals with asset exposure and business criticality.

  3. 3
    Remediate

    Follow the vendor advisory or supported update path and preserve rollback options.

  4. 4
    Verify

    Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
CWE
CWE-367
CVE-2026-4878 — Red Hat Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 10.0 Extended Update Support, Red Hat Enterprise Linux 8 | SECUFOCUS NOW