cvedb.io
CVE-2026-39860
CRITICAL · CVSS 9
EPSS exploitation probability: 0%
Published 2026-04-08T21:17:00.157 · Last modified 2026-06-17T10:42:43.027

Summary

Nix is a package manager for Linux and other Unix systems. A bug in the fix for CVE-2024-27297 allowed for arbitrary overwrites of files writable by the Nix process orchestrating the builds (typically the Nix daemon running as root in multi-user installations) by following symlinks during fixed-output derivation output registration. This affects sandboxed Linux builds - sandboxed macOS builds are unaffected. The location of the temporary output used for the output copy was located inside the build chroot. A symlink, pointing to an arbitrary location in the filesystem, could be created by the derivation builder at that path. During output registration, the Nix process (running in the host mount namespace) would follow that symlink and overwrite the destination with the derivation's output c

Affected products

nixos — nix

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References

This product uses data from the NVD API but is not endorsed or certified by the NVD. Informational only; not professional security advice.