Security researchers have disclosed a critical remote code execution vulnerability in libarchive, a widely used open-source library for handling compressed file formats. The flaw, tracked as CVE-2026-4187 with a CVSS score of 9.8, affects applications across Linux, macOS, and Windows that rely on the library for file extraction operations.
The vulnerability allows attackers to execute arbitrary code by crafting a malicious archive file that triggers a buffer overflow during extraction. Cybersecurity firm CrowdStrike estimates that the library is embedded in over 12 million applications and system utilities worldwide, making the patch rollout a significant undertaking for the software supply chain.
Maintainers have released patched versions for all supported branches, and major Linux distributions have begun pushing emergency updates. Organizations are urged to prioritize patching any internet-facing services that handle user-uploaded archive files.
