CVE-2026-4878

7.0

HIGH CVSS 3.1

Libcap: libcap: privilege escalation via toctou race condition in cap_set_file()

Overview

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.

Details

INFO

Published Date :

April 9, 2026, 4:16 p.m.

Last Modified :

April 28, 2026, 12:41 a.m.

Remotely Exploit :

No

Source :

[email protected]

Impact

Affected Products

The following products are affected by CVE-2026-4878 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID	Vendor	Product
1	Redhat	enterprise_linux
2	Redhat	openshift_container_platform
3	Redhat	hardened_images
1	Libcap_project	libcap

: Total Affected Vendor : 2 | Products : 4

Scoring

CVSS Scores

The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.

Version	Severity	Source
CVSS 3.1	MEDIUM	53f830b8-0a3f-465b-8143-3b8a9948e749
CVSS 3.1	MEDIUM	[email protected]
CVSS 3.1	MEDIUM	MITRE-CVE
CVSS 3.1	HIGH	[email protected]

Solution

Address the TOCTOU race condition in cap_set_file to prevent unauthorized capability modification.

Update the libcap library to the latest version.
Review file system access controls for sensitive directories.
Monitor for unexpected changes in file capabilities.

Public PoC/Exploit Available at Github

CVE-2026-4878 has a 3 public PoC/Exploit available at Github. Go to the Public Exploits tab to see the list.

References

References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-4878.

URL	Resource
https://access.redhat.com/errata/RHSA-2026:7473	Vendor Advisory
https://access.redhat.com/security/cve/CVE-2026-4878	Vendor Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2447554	Permissions Required
https://bugzilla.redhat.com/show_bug.cgi?id=2451615	Issue Tracking Vendor Advisory
http://www.openwall.com/lists/oss-security/2026/04/07/14	Mailing List Third Party Advisory
http://www.openwall.com/lists/oss-security/2026/04/07/4	Mailing List Third Party Advisory
http://www.openwall.com/lists/oss-security/2026/04/08/9	Mailing List Third Party Advisory
http://www.openwall.com/lists/oss-security/2026/04/09/5	Exploit Mailing List Third Party Advisory
http://www.openwall.com/lists/oss-security/2026/04/09/6	Exploit Mailing List Third Party Advisory

CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-4878 is associated with the following CWEs:

CWE-367: Time-of-check Time-of-use (TOCTOU) Race Condition

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-4878 weaknesses.

CAPEC-27: Leveraging Race Conditions via Symbolic Links Leveraging Race Conditions via Symbolic Links CAPEC-29: Leveraging Time-of-Check and Time-of-Use (TOCTOU) Race Conditions Leveraging Time-of-Check and Time-of-Use (TOCTOU) Race Conditions

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

MukeshKumarCloud/trivy-nginx-scan

trivy-nginx-scan

Updated: 2 weeks, 2 days ago

0 stars 0 fork 0 watcher

Born at : April 14, 2026, 1:37 p.m. This repo has been linked 106 different CVEs too.

Dynamo-Technologies/crewAI-federal

STIG-hardened crewAI for federal/DoD deployment

Dockerfile Python JavaScript Jinja CSS Shell

Updated: 4 days, 21 hours ago

0 stars 0 fork 0 watcher

Born at : April 9, 2026, 7:09 p.m. This repo has been linked 2 different CVEs too.

fkie-cad/nvd-json-data-feeds

Community reconstruction of the legacy JSON NVD Data Feeds. This project uses and redistributes data from the NVD API but is neither endorsed nor certified by the NVD.

Shell

Updated: 5 days, 11 hours ago

216 stars 26 fork 26 watcher

Born at : May 17, 2023, 8 a.m. This repo has been linked 19 different CVEs too.

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-4878 vulnerability anywhere in the article.

Results are limited to the first 20 news articles due to potential performance issues.

The following table lists the changes that have been made to the CVE-2026-4878 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

Initial Analysis by [email protected]

Apr. 28, 2026

Action	Type	New Value
Added	CVSS V3.1	AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
Added	CPE Configuration	OR cpe:2.3:o:redhat:enterprise_linux:8.0::::::: cpe:2.3:a:redhat:openshift_container_platform:4.0::::::: cpe:2.3:o:redhat:enterprise_linux:9.0::::::: cpe:2.3:a:libcap_project:libcap:-::::::: cpe:2.3:o:redhat:enterprise_linux:10.0:::::::
Added	Reference Type	CVE: http://www.openwall.com/lists/oss-security/2026/04/07/14 Types: Mailing List, Third Party Advisory
Added	Reference Type	CVE: http://www.openwall.com/lists/oss-security/2026/04/07/4 Types: Mailing List, Third Party Advisory
Added	Reference Type	CVE: http://www.openwall.com/lists/oss-security/2026/04/08/9 Types: Mailing List, Third Party Advisory
Added	Reference Type	CVE: http://www.openwall.com/lists/oss-security/2026/04/09/5 Types: Exploit, Mailing List, Third Party Advisory
Added	Reference Type	CVE: http://www.openwall.com/lists/oss-security/2026/04/09/6 Types: Exploit, Mailing List, Third Party Advisory
Added	Reference Type	Red Hat, Inc.: https://access.redhat.com/errata/RHSA-2026:7473 Types: Vendor Advisory
Added	Reference Type	Red Hat, Inc.: https://access.redhat.com/security/cve/CVE-2026-4878 Types: Vendor Advisory
Added	Reference Type	Red Hat, Inc.: https://bugzilla.redhat.com/show_bug.cgi?id=2447554 Types: Permissions Required
Added	Reference Type	Red Hat, Inc.: https://bugzilla.redhat.com/show_bug.cgi?id=2451615 Types: Issue Tracking, Vendor Advisory

CVE Modified by [email protected]

Apr. 25, 2026

Action	Type	Old Value	New Value
Added	Reference		https://access.redhat.com/errata/RHSA-2026:7473

New CVE Received by [email protected]

Apr. 09, 2026

Action	Type	New Value
Added	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.
Added	CVSS V3.1	AV:L/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:H
Added	CWE	CWE-367
Added	Reference	https://access.redhat.com/security/cve/CVE-2026-4878
Added	Reference	https://bugzilla.redhat.com/show_bug.cgi?id=2447554
Added	Reference	https://bugzilla.redhat.com/show_bug.cgi?id=2451615

CVE Modified by af854a3a-2127-422b-91ae-364da2661108