Libcap: libcap: privilege escalation via toctou race condition in cap_set_file()
Summary
| CVE | CVE-2026-4878 |
|---|---|
| State | PUBLISHED |
| Assigner | redhat |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-04-09 16:16:31 UTC |
| Updated | 2026-04-25 02:16:03 UTC |
| 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. |
Risk And Classification
Primary CVSS: v3.1 6.7 MEDIUM from [email protected]
CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:H
EPSS: 0.000110000 probability, percentile 0.013320000 (date 2026-04-15)
Problem Types: CWE-367 | CWE-367 Time-of-check Time-of-use (TOCTOU) Race Condition
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | [email protected] | Secondary | 6.7 | MEDIUM | CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:H |
| 3.1 | CNA | CVSS | 6.7 | MEDIUM | CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:H |
CVSS v3.1 Breakdown
Attack Vector
LocalAttack Complexity
HighPrivileges Required
LowUser Interaction
RequiredScope
UnchangedConfidentiality
HighIntegrity
HighAvailability
HighCVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:H
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Red Hat | Red Hat Hardened Images | unaffected 2.78-1.1.hum1 * rpm | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 10 | Not specified | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 6 | Not specified | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 6 | Not specified | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 7 | Not specified | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 7 | Not specified | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 8 | Not specified | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 9 | Not specified | Not specified |
| CNA | Red Hat | Red Hat OpenShift Container Platform 4 | Not specified | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| access.redhat.com/errata/RHSA-2026:7473 | [email protected] | access.redhat.com | |
| www.openwall.com/lists/oss-security/2026/04/07/14 | af854a3a-2127-422b-91ae-364da2661108 | www.openwall.com | |
| www.openwall.com/lists/oss-security/2026/04/07/4 | af854a3a-2127-422b-91ae-364da2661108 | www.openwall.com | |
| www.openwall.com/lists/oss-security/2026/04/09/6 | af854a3a-2127-422b-91ae-364da2661108 | www.openwall.com | |
| access.redhat.com/security/cve/CVE-2026-4878 | [email protected] | access.redhat.com | |
| www.openwall.com/lists/oss-security/2026/04/09/5 | af854a3a-2127-422b-91ae-364da2661108 | www.openwall.com | |
| bugzilla.redhat.com/show_bug.cgi | [email protected] | bugzilla.redhat.com | |
| www.openwall.com/lists/oss-security/2026/04/08/9 | af854a3a-2127-422b-91ae-364da2661108 | www.openwall.com | |
| bugzilla.redhat.com/show_bug.cgi | [email protected] | bugzilla.redhat.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Red Hat would like to thank Ali Raza for reporting this issue. (en)
Additional Advisory Data
| Source | Time | Event |
|---|---|---|
| CNA | 2026-03-26T06:56:21.213Z | Reported to Red Hat. |
| CNA | 2026-04-06T00:00:00.000Z | Made public. |
Workarounds
CNA: Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
There are currently no legacy QID mappings associated with this CVE.