FreeBSD-SA-26:17.libnv Security Advisory Summary Vulnerability Overview Vulnerability Name: Heap overflow in libnv CVE ID: CVE-2026-35547 Description: failed to properly validate message sizes when processing incoming message headers. This allows malicious programs to write beyond heap allocation boundaries, potentially causing system crashes or panics, and may be exploited by unprivileged users to escalate privileges. Affected Versions Affected Module: libnv Affected Versions: All supported FreeBSD versions. Stable: stable/15, 15.0-STABLE Release: releng/15.0, 15.0-RELEASE-p7 Stable: stable/14, 14.4-STABLE Release: releng/14.4, 14.4-RELEASE-p3 Stable: stable/13, 13.5-STABLE * Release: releng/13.5, 13.5-RELEASE-p13 Remediation It is recommended to upgrade vulnerable systems to FreeBSD stable or release/security branches (releng) dated after the fix date. Method 1: Update Base System Packages Applies to FreeBSD 15.0-RELEASE versions installed using base system packages (amd64 or arm64 platforms). Method 2: Update Binary Distribution System Applies to FreeBSD versions installed using binary distributions (amd64 or arm64 platforms), or the i386 platform on FreeBSD 11. Method 3: Update via Source Code Patch Applies to systems built from source. 1. Download the patch and verify the PGP signature: 2. Apply the patch: 3. Rebuild the kernel and reboot: