{
  "schemaVersion": 1,
  "attribution": [
    {
      "source": "CISA Known Exploited Vulnerabilities",
      "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog",
      "licence": "US government work"
    },
    {
      "source": "GitHub Advisory Database",
      "url": "https://github.com/advisories",
      "licence": "CC BY 4.0"
    },
    {
      "source": "Have I Been Pwned",
      "url": "https://haveibeenpwned.com/",
      "licence": "CC BY 4.0"
    },
    {
      "source": "CVE Program (CVE records)",
      "url": "https://www.cve.org/Legal/TermsOfUse",
      "licence": "CVE Terms of Use",
      "notice": "Copyright © 1999-2026, The MITRE Corporation. CVE is a trademark and the CVE logo is a registered trademark of The MITRE Corporation.",
      "terms": "CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE™). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy."
    },
    {
      "source": "FIRST EPSS",
      "url": "https://www.first.org/epss/",
      "licence": "free to use; FIRST requests attribution"
    }
  ],
  "record": {
    "id": "CVE-2026-39860",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2026-39860",
    "idYear": 2026,
    "status": "PUBLISHED",
    "publishedAt": "2026-04-08T20:58:22.979Z",
    "updatedAt": "2026-04-09T13:42:36.997Z",
    "importedAt": "2026-10-24T01:58:08.712Z",
    "snapshot": {
      "id": "cve_2026-10-24_midnight_baseline",
      "at": "2026-10-24T00:00:00.000Z",
      "source": "https://github.com/CVEProject/cvelistV5/releases/tag/cve_2026-10-24_0100Z"
    },
    "facts": {
      "title": "Nix sandbox escape: file write via symlink at FOD `.tmp` copy destination",
      "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 contents. In multi-user installations, this allows all users able to submit builds to the Nix daemon (allowed-users - defaulting to all users) to gain root privileges by modifying sensitive files. This vulnerability is fixed in 2.34.5, 2.33.4, 2.32.7, 2.31.4, 2.30.4, 2.29.3, and 2.28.6.",
      "affected": [
        {
          "vendor": "NixOS",
          "product": "nix",
          "versions": [
            {
              "version": ">= 2.21, < 2.28.6",
              "status": "affected"
            },
            {
              "version": ">= 2.29.0, < 2.29.3",
              "status": "affected"
            },
            {
              "version": ">= 2.30.0, < 2.30.4",
              "status": "affected"
            },
            {
              "version": ">= 2.31.0, < 2.31.4",
              "status": "affected"
            },
            {
              "version": ">= 2.32.0, < 2.32.7",
              "status": "affected"
            },
            {
              "version": ">= 2.33.0, < 2.33.4",
              "status": "affected"
            },
            {
              "version": ">= 2.34.0, < 2.34.5",
              "status": "affected"
            },
            {
              "version": ">= 2.20.5, <= 2.20.9",
              "status": "affected"
            },
            {
              "version": ">= 2.19.4, <= 2.19.7",
              "status": "affected"
            },
            {
              "version": ">= 2.18.2, <= 2.18.9",
              "status": "affected"
            }
          ]
        }
      ]
    }
  }
}