Libcap: libcap: privilege escalation via toctou race condition in cap_set_file()
CVE-2026-4878 is fixed in 6 products on 1 platform, first by RHSA-2026:19456, released April 6, 2026. It is not reported as exploited. Patch Radar priority: High.
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.
Where it's fixed
| Product | Fixed in | Fix | Released |
|---|---|---|---|
| Linux | |||
| golang-kernel-pub-linux-libs-security-libcap-dev · Ubuntu 25.10 (questing) | 1:2.75-7ubuntu2.2 | golang-kernel-pub-linux-libs-security-libcap-dev 1:2.75-7ubuntu2.2 | Apr 9, 2026 |
| libcap · RHEL 10 | 2.69-7.el10_0.1 | RHSA-2026:19456 | Apr 6, 2026 |
| libcap · RHEL 8 | 0:2.48-6.el8_10.1 | RHSA-2026:13285 | May 15, 2026 |
| libcap · RHEL 9 | 0:2.48-10.el9_8.1 | RHSA-2026:19346 | May 15, 2026 |
| libcap · almalinux 10 | 2.69-7.el10_2.1 | ALSA-2026:19130 | May 19, 2026 |
| libcap · almalinux 8 | 2.48-6.el8_10.1 | ALSA-2026:13285 | May 4, 2026 |
| libcap · almalinux 9 | 2.48-10.el9_8.1 | ALSA-2026:19346 | May 19, 2026 |
| libcap · ol 10 | 0:2.69-7.el10_1.1 | ELSA-2026-12423 | Apr 30, 2026 |
| libcap · ol 8 | 0:2.48-6.el8_10.1 | ELSA-2026-13285 | May 5, 2026 |
| libcap · ol 9 | 0:2.48-10.el9_7.1 | ELSA-2026-12441 | Apr 30, 2026 |
| libcap · opensuse-leap 16.0 | 2.73-160000.3.1 | OPENSUSE-SU-2026:20613-1 | Apr 22, 2026 |
| libcap · rocky 10 | 0:2.69-7.el10_1.1 | RLSA-2026:19130 | May 29, 2026 |
| libcap · rocky 8 | 0:2.48-6.el8_10.1 | RLSA-2026:13285 | May 6, 2026 |
| libcap · rocky 9 | 0:2.48-10.el9_7.1 | RLSA-2026:19346 | May 20, 2026 |
| libcap · sles 15.6 | 2.63-150400.3.6.1 | SUSE-SU-2026:1432-1 | Apr 17, 2026 |
| libcap · sles 15.7 | 2.63-150400.3.6.1 | SUSE-SU-2026:1432-1 | Apr 17, 2026 |
| libcap-devel · RHEL 8 | 0:2.48-6.el8_10.1 | RHSA-2026:13285 | May 15, 2026 |
| libcap-devel · RHEL 9 | 0:2.48-10.el9_8.1 | RHSA-2026:19346 | May 15, 2026 |
| libcap-devel · almalinux 10 | 2.69-7.el10_2.1 | ALSA-2026:19130 | May 19, 2026 |
| libcap-devel · almalinux 8 | 2.48-6.el8_10.1 | ALSA-2026:13285 | May 4, 2026 |
| libcap-devel · almalinux 9 | 2.48-10.el9_8.1 | ALSA-2026:19346 | May 19, 2026 |
| libcap-devel · ol 10 | 0:2.69-7.el10_1.1 | ELSA-2026-12423 | Apr 30, 2026 |
| libcap-devel · ol 8 | 0:2.48-6.el8_10.1 | ELSA-2026-13285 | May 5, 2026 |
| libcap-devel · ol 9 | 0:2.48-10.el9_7.1 | ELSA-2026-12441 | Apr 30, 2026 |
| libcap2 · Debian 12.15 (bookworm) | 1:2.66-4+deb12u3 | DEBIAN-CVE-2026-4878 | Apr 9, 2026 |
| libcap2 · Debian 13.5 (trixie) | 1:2.75-10+deb13u1 | DEBIAN-CVE-2026-4878 | Apr 9, 2026 |
| libcap2 · Debian 14 | 1:2.78-1 | DEBIAN-CVE-2026-4878 | Apr 9, 2026 |
| libcap2 · Ubuntu 18.04.6 LTS (bionic) | 1:2.25-1.2ubuntu0.1~esm2 | libcap2 1:2.25-1.2ubuntu0.1~esm2 | Apr 9, 2026 |
| libcap2 · Ubuntu 20.04 LTS (focal) | 1:2.32-1ubuntu0.2+esm1 | libcap2 1:2.32-1ubuntu0.2+esm1 | Apr 9, 2026 |
| libcap2 · Ubuntu 22.04.1 LTS (jammy) | 1:2.44-1ubuntu0.22.04.3 | libcap2 1:2.44-1ubuntu0.22.04.3 | Apr 30, 2026 |
| libcap2 · Ubuntu 24.04.5 LTS (noble) | 1:2.66-5ubuntu2.4 | libcap2 1:2.66-5ubuntu2.4 | Apr 30, 2026 |
| libcap2 · Ubuntu 25.10 (questing) | 1:2.75-7ubuntu2.2 | libcap2 1:2.75-7ubuntu2.2 | Apr 30, 2026 |
| libcap2-bin · Ubuntu 18.04.6 LTS (bionic) | 1:2.25-1.2ubuntu0.1~esm2 | libcap2-bin 1:2.25-1.2ubuntu0.1~esm2 | Apr 9, 2026 |
| libcap2-bin · Ubuntu 20.04 LTS (focal) | 1:2.32-1ubuntu0.2+esm1 | libcap2-bin 1:2.32-1ubuntu0.2+esm1 | Apr 9, 2026 |
| libcap2-bin · Ubuntu 22.04.1 LTS (jammy) | 1:2.44-1ubuntu0.22.04.3 | libcap2-bin 1:2.44-1ubuntu0.22.04.3 | Apr 30, 2026 |
| libcap2-bin · Ubuntu 24.04.5 LTS (noble) | 1:2.66-5ubuntu2.4 | libcap2-bin 1:2.66-5ubuntu2.4 | Apr 30, 2026 |
| libcap2-bin · Ubuntu 25.10 (questing) | 1:2.75-7ubuntu2.2 | libcap2-bin 1:2.75-7ubuntu2.2 | Apr 30, 2026 |
| libpam-cap · Ubuntu 18.04.6 LTS (bionic) | 1:2.25-1.2ubuntu0.1~esm2 | libpam-cap 1:2.25-1.2ubuntu0.1~esm2 | Apr 9, 2026 |
| libpam-cap · Ubuntu 20.04 LTS (focal) | 1:2.32-1ubuntu0.2+esm1 | libpam-cap 1:2.32-1ubuntu0.2+esm1 | Apr 9, 2026 |
| libpam-cap · Ubuntu 22.04.1 LTS (jammy) | 1:2.44-1ubuntu0.22.04.3 | libpam-cap 1:2.44-1ubuntu0.22.04.3 | Apr 30, 2026 |
| libpam-cap · Ubuntu 24.04.5 LTS (noble) | 1:2.66-5ubuntu2.4 | libpam-cap 1:2.66-5ubuntu2.4 | Apr 30, 2026 |
| libpam-cap · Ubuntu 25.10 (questing) | 1:2.75-7ubuntu2.2 | libpam-cap 1:2.75-7ubuntu2.2 | Apr 30, 2026 |
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