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.
CVE-2026-4878
This high-severity CVE scores 7.0 under NVD CVSS v3. EPSS exploit probability: 0.0%, top 98% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
- High severity, but no confirmed exploitation yet
A fix is available — apply it.
- CVSS v3
- 7.0
- EG Score
- 7.0(medium)
- EPSS
- 8.6%
- KEV
- Not listed
Published
April 9, 2026
Last Modified
July 10, 2026
Advisory Details (10)
Auto-updated Apr 30, 2026oss-security - Re: libcap-2.77 (since libcap-2.04) has TOCTOU privilege escalation issue
http://www.openwall.com/lists/oss-security/2026/04/09/5oss-security - Re: libcap-2.77 (since libcap-2.04) has TOCTOU privilege escalation issue
http://www.openwall.com/lists/oss-security/2026/04/08/9oss-security - libcap-2.77 (since libcap-2.04) has TOCTOU privilege escalation issue
http://www.openwall.com/lists/oss-security/2026/04/07/4oss-security - Re: libcap-2.77 (since libcap-2.04) has TOCTOU privilege escalation issue
http://www.openwall.com/lists/oss-security/2026/04/07/142451615 – (CVE-2026-4878) CVE-2026-4878 libcap: libcap: Privilege escalation via TOCTOU race condition in cap_set_file()
Affected: Red Hat Enterprise Linux 10
https://bugzilla.redhat.com/show_bug.cgi?id=2451615Affected: Red Hat Enterprise Linux 9.
https://access.redhat.com/errata/RHSA-2026:12441Affected: Red Hat Enterprise Linux 10.
https://access.redhat.com/errata/RHSA-2026:12423Vendor Advisories for CVE-2026-4878(20)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
- RHSA-2026:34098Red Hat Product SecurityCritical
Red Hat Security Advisory: OpenShift Container Platform 4.17.55 bug fix and security update
- RHSA-2026:28887Red Hat Product SecurityCritical
Red Hat Security Advisory: OpenShift Container Platform 4.14.68 bug fix and security update
- RHSA-2026:30089Red Hat Product SecurityCritical
Red Hat Security Advisory: Red Hat AI Inference Server 3.3.5 (CUDA)
- RHSA-2026:30088Red Hat Product SecurityCritical
Red Hat Security Advisory: Red Hat AI Inference Server 3.3.5 (ROCm)
- RHSA-2026:30087Red Hat Product SecurityCritical
Red Hat Security Advisory: Red Hat AI Inference Server 3.3.5 (Spyre)
- RHSA-2026:30078Red Hat Product SecurityHigh
Red Hat Security Advisory: Red Hat AI Inference Server Model Optimization Tools 3.3.5 (CUDA)
- RHSA-2026:26542Red Hat Product SecurityCritical
Red Hat Security Advisory: OpenShift Container Platform 4.13.68 bug fix and security update
- RHSA-2026:29197Red Hat Product SecurityHigh
Red Hat Security Advisory: A Subscription Management tool for finding and reporting Red Hat product usage
- +12 more
Patch Availability(19)
Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Additional Vendor Advisories
(11)
Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.
- Red HatRHSA-2026:12423IMPORTANT2026-04-06
RHSA-2026:12423 — Important
- Red HatRHSA-2026:12441IMPORTANT2026-04-06
RHSA-2026:12441 — Important
- Red HatRHSA-2026:13285IMPORTANT2026-04-06
RHSA-2026:13285 — Important
- Red HatRHSA-2026:14162IMPORTANT2026-04-06
RHSA-2026:14162 — Important
- Red HatRHSA-2026:14937IMPORTANT2026-04-06
RHSA-2026:14937 — Important
- Red HatRHSA-2026:19130IMPORTANT2026-04-06
RHSA-2026:19130 — Important
- Red HatRHSA-2026:19346IMPORTANT2026-04-06
RHSA-2026:19346 — Important
- Red HatRHSA-2026:19456IMPORTANT2026-04-06
RHSA-2026:19456 — Important
- Red HatRHSA-2026:19458IMPORTANT2026-04-06
RHSA-2026:19458 — Important
- Red HatRHSA-2026:20595IMPORTANT2026-04-06
RHSA-2026:20595 — Important
- Red HatRHSA-2026:7473IMPORTANT2026-04-06
RHSA-2026:7473 — Important
Data Freshness Timeline
(refreshed 13× in last 7d / 49× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-07-12 05:46 UTCEPSS rescore
- 2026-07-11 08:27 UTCEPSS rescore
- 2026-07-11 08:27 UTCEPSS rescore
- 2026-07-10 12:26 UTCNVD updateCVSS v3 → 7 · severity → HIGH
- 2026-07-10 12:12 UTCMITRE cvelistV5CVSS v3 → 6.7 · severity → MEDIUM
- 2026-07-09 19:10 UTCEPSS rescore
- 2026-07-09 19:10 UTCEPSS rescore
- 2026-07-09 19:01 UTCNVD updateCVSS v3 → 7 · severity → HIGH
- 2026-07-09 17:56 UTCMITRE cvelistV5CVSS v3 → 6.7 · severity → MEDIUM
- 2026-07-08 15:16 UTCEPSS rescore
- 2026-07-07 13:46 UTCEPSS rescore
- 2026-07-06 16:27 UTCEPSS rescore
- 2026-07-06 02:23 UTCEPSS rescore
- 2026-07-05 02:30 UTCEPSS rescore
- 2026-07-04 06:31 UTCEPSS rescore
- 2026-07-01 15:07 UTCEPSS rescore
- 2026-06-30 23:22 UTCEPSS rescore
- 2026-06-29 14:06 UTCEPSS rescore
- 2026-06-29 14:06 UTCEPSS rescore
- 2026-06-28 14:07 UTCEPSS rescore
- 2026-06-28 04:56 UTCEPSS rescore
- 2026-06-28 04:56 UTCEPSS rescore
- 2026-06-27 09:36 UTCNVD updateCVSS v3 → 7 · severity → HIGH
- 2026-06-27 08:19 UTCMITRE cvelistV5CVSS v3 → 6.7 · severity → MEDIUM
- 2026-06-27 03:08 UTCEPSS rescore
Show 72 moreShow fewer
- 2026-06-25 13:49 UTCEPSS rescore
- 2026-06-24 14:05 UTCEPSS rescore
- 2026-06-23 21:33 UTCEPSS rescore
- 2026-06-23 21:33 UTCEPSS rescore
- 2026-06-22 14:25 UTCEPSS rescore
- 2026-06-22 14:25 UTCEPSS rescore
- 2026-06-21 14:56 UTCEPSS rescore
- 2026-06-21 14:56 UTCEPSS rescore
- 2026-06-21 01:59 UTCEPSS rescore
- 2026-06-21 01:59 UTCEPSS rescore
- 2026-06-19 19:26 UTCEPSS rescore
- 2026-06-19 19:26 UTCEPSS rescore
- 2026-06-18 17:52 UTCEPSS rescore
- 2026-06-18 17:52 UTCEPSS rescore
- 2026-06-17 17:53 UTCEPSS rescore
- 2026-06-16 17:53 UTCEPSS rescore
- 2026-06-15 17:49 UTCEPSS rescore
- 2026-06-15 17:49 UTCEPSS rescore
- 2026-06-15 05:03 UTCEG score recompute
- 2026-06-15 05:03 UTCVendor advisory
- 2026-06-14 23:18 UTCEPSS rescore
- 2026-06-13 23:00 UTCEPSS rescore
- 2026-06-12 23:12 UTCEPSS rescore
- 2026-06-12 23:12 UTCEPSS rescore
- 2026-06-11 20:31 UTCEG score recompute
- 2026-06-11 20:31 UTCVendor advisory
- 2026-06-11 14:00 UTCEPSS rescore
- 2026-06-10 22:19 UTCEPSS rescore
- 2026-06-10 13:22 UTCEPSS rescore
- 2026-06-10 12:47 UTCEG score recompute
- 2026-06-10 12:47 UTCVendor advisory
- 2026-06-10 01:02 UTCEG score recompute
- 2026-06-10 01:02 UTCVendor advisory
- 2026-06-09 13:04 UTCEG score recompute▲ 0.30
- 2026-06-09 13:04 UTCVendor advisory
- 2026-06-08 23:31 UTCNVD updateCVSS v3 → 7 · severity → HIGH
- 2026-06-08 14:17 UTCEPSS rescore
- 2026-06-08 14:17 UTCEPSS rescore
- 2026-06-08 08:26 UTCEG score recompute
- 2026-06-08 08:26 UTCVendor advisory
- 2026-06-07 15:25 UTCEPSS rescore
- 2026-06-07 15:25 UTCEPSS rescore
- 2026-06-07 08:36 UTCEG score recompute
- 2026-06-07 08:36 UTCVendor advisory
- 2026-06-06 13:47 UTCEPSS rescore
- 2026-06-06 13:47 UTCEPSS rescore
- 2026-06-05 22:47 UTCEPSS rescore
- 2026-06-05 06:10 UTCEPSS rescore
- 2026-06-05 06:10 UTCEPSS rescore
- 2026-06-04 13:12 UTCEPSS rescore
- 2026-06-04 13:12 UTCEPSS rescore
- 2026-06-02 20:13 UTCEPSS rescore
- 2026-06-01 13:52 UTCEPSS rescore
- 2026-06-01 13:52 UTCEPSS rescore
- 2026-05-31 22:30 UTCEPSS rescore
- 2026-05-31 22:30 UTCEPSS rescore
- 2026-05-31 00:16 UTCEPSS rescore
- 2026-05-31 00:16 UTCEPSS rescore
- 2026-05-29 13:44 UTCEPSS rescore
- 2026-05-29 13:44 UTCEPSS rescore
- 2026-05-28 13:44 UTCEPSS rescore
- 2026-05-28 13:44 UTCEPSS rescore
- 2026-05-27 13:40 UTCEPSS rescore
- 2026-05-27 13:40 UTCEPSS rescore
- 2026-05-26 13:44 UTCEPSS rescore
- 2026-05-26 07:18 UTCEPSS rescore
- 2026-05-23 00:08 UTCEG score recompute
- 2026-05-21 22:43 UTCEPSS rescore
- 2026-05-20 22:38 UTCEPSS rescore
- 2026-05-20 18:06 UTCEG score recompute
- 2026-05-20 18:06 UTCVendor advisory
- 2026-05-20 11:22 UTCEPSS rescore
Frequently asked(5)
What is CVE-2026-4878?
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What is the CVSS score of CVE-2026-4878?
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