cabal-install dependency confusion

{
  "affected": [
    {
      "database_specific": {
        "human_link": "https://github.com/haskell/security-advisories/tree/main/advisories/published/2025/HSEC-2025-0005.md",
        "osv": "https://raw.githubusercontent.com/haskell/security-advisories/refs/heads/generated/osv-export/2025/HSEC-2025-0005.json"
      },
      "package": {
        "ecosystem": "Hackage",
        "name": "cabal-install"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "1.0.0.0"
            },
            {
              "fixed": "3.4.0.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "severity": [
        {
          "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:N",
          "type": "CVSS_V3"
        }
      ]
    }
  ],
  "database_specific": {
    "home": "https://github.com/haskell/security-advisories",
    "osvs": "https://raw.githubusercontent.com/haskell/security-advisories/refs/heads/generated/osv-export",
    "repository": "https://github.com/haskell/security-advisories"
  },
  "details": "# `cabal-install` dependency confusion\n\nFor **cabal-install \u003c 3.4.0.0** and where multiple repositories are\nconfigured, the resolver picks the highest available version across\nall repositories.  Where a package is only defined in a private\nrepository, this behaviour leads to a [*dependency confusion*][blog]\nsupply chain vulnerability.  If the private package name becomes\nknown, a malicious actor can claim the name in the public repository\nand publish a malicious version at a higher version number.\n\nDefault `cabal-install` configurations that only use the\n`hackage.haskell.org` repository are not affected.  Configurations\nthat use curated private repositories **exclusively** are also not\naffected.\n\n[blog]: https://frasertweedale.github.io/blog-fp/posts/2021-02-12-haskell-dependency-confusion.html\n\n\n## Mitigations\n\n*cabal-install* version **3.4.0.0** and higher provide an `override`\noption in the repository configuration.  It marks the associated\nrepository as canonical for all packages defined in that repository.\nNo other repositories will be considered.  For example:\n\n```\n-- For packages in repo.example.com,\n-- only versions in repo.example.com are considered\nactive-repositories:\n  , hackage.haskell.org\n  , repo.example.com:override\n```\n\nUsers and organisations using private repositories that contain\nprivate packages in addition to public repositories **MUST** use the\n`override` option to prevent dependency confusion attacks.\n\nAlternatively, projects and organisations can run a private instance\nof *hackage-server* and carefully curate and review its contents.\nUsing that instance exclusively defeats supply chain attacks\nincluding *dependency confusion*.  For *cabal-install \u003c 3.4* and\nwhere using multiple repositories, this is the only effective\nmitigation against dependency confusion attacks.\n",
  "id": "HSEC-2025-0005",
  "modified": "2025-11-14T14:45:34Z",
  "published": "2025-11-14T14:45:34Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://frasertweedale.github.io/blog-fp/posts/2021-02-12-haskell-dependency-confusion.html"
    }
  ],
  "schema_version": "1.5.0",
  "summary": "cabal-install dependency confusion"
}