ubuntu-cve-2026-44028
Vulnerability from osv_ubuntu
Published
2026-05-05 01:16
Modified
2026-05-20 15:28
Summary
Details

An issue was discovered in Nix before 2.34.7 and Lix before 2.95.2. Unbounded recursion in the NAR (Nix Archive) parser could lead to a stack-to-heap overflow when the parser is run on a coroutine stack. The stack is allocated without a guard page, which means that a stack overflow could overwrite memory on the heap and could allow arbitrary code execution as the Nix daemon (run as root in multi-user installations) if ASLR hardening is bypassed. This can be exploited by all users able to connect to the daemon (e.g., in Nix, this is configurable via the allowed-users setting, defaulting to all users). The fixed versions are 2.34.7, 2.33.6, 2.32.8, 2.31.5, 2.30.5, 2.29.4, and 2.28.7 for Nix (introduced in 2.24.4); and 2.95.2, 2.94.2, and 2.93.4 for Lix (introduced in 2.93.0).

Severity
7.5 (High)
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:N
N/A (UNKNOWN)
medium
References
To clipboard 

{
  "affected": [
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "nix-bin",
            "binary_version": "2.6.0+dfsg-3ubuntu0.1~esm1"
          },
          {
            "binary_name": "nix-setup-systemd",
            "binary_version": "2.6.0+dfsg-3ubuntu0.1~esm1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:22.04:LTS",
        "name": "nix",
        "purl": "pkg:deb/ubuntu/nix@2.6.0+dfsg-3ubuntu0.1~esm1?arch=source\u0026distro=esm-apps/jammy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "2.3.10+dfsg1-1",
        "2.3.10+dfsg1-1build1",
        "2.6.0+dfsg-2",
        "2.6.0+dfsg-3",
        "2.6.0+dfsg-3ubuntu0.1~esm1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "nix-bin",
            "binary_version": "2.18.1+dfsg-1ubuntu5+esm2"
          },
          {
            "binary_name": "nix-setup-systemd",
            "binary_version": "2.18.1+dfsg-1ubuntu5+esm2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:24.04:LTS",
        "name": "nix",
        "purl": "pkg:deb/ubuntu/nix@2.18.1+dfsg-1ubuntu5+esm2?arch=source\u0026distro=esm-apps/noble"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "2.16.1+dfsg-3ubuntu1",
        "2.18.1+dfsg-1ubuntu1",
        "2.18.1+dfsg-1ubuntu2",
        "2.18.1+dfsg-1ubuntu4",
        "2.18.1+dfsg-1ubuntu5",
        "2.18.1+dfsg-1ubuntu5+esm2"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "nix-bin",
            "binary_version": "2.26.3+dfsg-1ubuntu4"
          },
          {
            "binary_name": "nix-setup-systemd",
            "binary_version": "2.26.3+dfsg-1ubuntu4"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:25.10",
        "name": "nix",
        "purl": "pkg:deb/ubuntu/nix@2.26.3+dfsg-1ubuntu4?arch=source\u0026distro=questing"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "2.24.9+dfsg-2ubuntu2",
        "2.26.3+dfsg-1ubuntu1",
        "2.26.3+dfsg-1ubuntu2",
        "2.26.3+dfsg-1ubuntu4"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "nix-bin",
            "binary_version": "2.34.3+dfsg-1"
          },
          {
            "binary_name": "nix-setup-systemd",
            "binary_version": "2.34.3+dfsg-1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:26.04:LTS",
        "name": "nix",
        "purl": "pkg:deb/ubuntu/nix@2.34.3+dfsg-1?arch=source\u0026distro=resolute"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "2.26.3+dfsg-1ubuntu4",
        "2.26.3+dfsg-1ubuntu5",
        "2.32.5+dfsg-1ubuntu3",
        "2.32.5+dfsg-2ubuntu1",
        "2.34.3+dfsg-1"
      ]
    }
  ],
  "aliases": [],
  "details": "An issue was discovered in Nix before 2.34.7 and Lix before 2.95.2. Unbounded recursion in the NAR (Nix Archive) parser could lead to a stack-to-heap overflow when the parser is run on a coroutine stack. The stack is allocated without a guard page, which means that a stack overflow could overwrite memory on the heap and could allow arbitrary code execution as the Nix daemon (run as root in multi-user installations) if ASLR hardening is bypassed. This can be exploited by all users able to connect to the daemon (e.g., in Nix, this is configurable via the allowed-users setting, defaulting to all users). The fixed versions are 2.34.7, 2.33.6, 2.32.8, 2.31.5, 2.30.5, 2.29.4, and 2.28.7 for Nix (introduced in 2.24.4); and 2.95.2, 2.94.2, and 2.93.4 for Lix (introduced in 2.93.0).",
  "id": "UBUNTU-CVE-2026-44028",
  "modified": "2026-05-20T15:28:57Z",
  "published": "2026-05-05T01:16:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-44028"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-44028"
    },
    {
      "type": "REPORT",
      "url": "https://discourse.nixos.org/t/security-advisory-local-privilege-escalation-in-lix-and-nix/77407"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/NixOS/nix/security/advisories/GHSA-vh5x-56v6-4368"
    },
    {
      "type": "REPORT",
      "url": "https://www.openwall.com/lists/oss-security/2026/05/04/33"
    }
  ],
  "related": [],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:N",
      "type": "CVSS_V3"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2026-44028"
  ]
}



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