Low
nix — security advisory
Nix is a package manager for Linux and other Unix systems. Prior to 2.35.0, a malicious derivation executed with the recursive-nix experimental feature can exploit a time-of-check/time-of-use race involving final symlink handling in the LocalStore restore path. The race can cause writeFile to follow a substituted final symlink when opening a path with O_TRUNC instead of enforcing FinalSymlink::DontFollow, allowing the Nix process or nix-daemon to create or truncate an empty file outside the build sandbox with the daemon user's permissions. The primitive does not provide arbitrary-content writes and requires winning the race. This issue is fixed in version 2.35.0.
- Products
- nix
- Affected versions
- 2.16.1+dfsg-1, 2.16.1+dfsg-2, 2.16.1+dfsg-3, 2.17.1+dfsg-1, 2.18.1+dfsg-1, 2.22.1+dfsg-1, 2.23.3+dfsg-1, 2.23.3+dfsg-2, 2.24.12+dfsg-1, 2.24.8+dfsg-1, 2.24.9+dfsg-1, 2.24.9+dfsg-2, 2.25.4+dfsg-1, 2.26.3+dfsg-1, 2.32.5+dfsg-1, 2.32.5+dfsg-2, 2.34.3+dfsg-1, 2.34.6+dfsg-1, 2.34.8+dfsg-1, 2.8.0-1.1
- Fixed versions
- Not specified
- CVEs
- CVE-2026-64846
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 22:37 UTC · Revision 1
Source evidence
Nix is a package manager for Linux and other Unix systems. Prior to 2.35.0, a malicious derivation executed with the recursive-nix experimental feature can exploit a time-of-check/time-of-use race involving final symlink handling in the LocalStore restore path. The race can cause writeFile to follow a substituted final symlink when opening a path with O_TRUNC instead of enforcing FinalSymlink::DontFollow, allowing the Nix process or nix-daemon to create or truncate an empty file outside the build sandbox with the daemon user's permissions. The primitive does not provide arbitrary-content writes and requires winning the race. This issue is fixed in version 2.35.0.
osv:DEBIAN-CVE-2026-64846
nix
Fixed versions: Not specified
nix
Fixed versions: Not specified
nix
Fixed versions: Not specified
Complete source record
{
"id": "6cb24cffc64fba78663b54cbd31cb109decc2c5d4d8c6ba2f4cc14fffb68a23c",
"url": "https://osv.dev/vulnerability/DEBIAN-CVE-2026-64846",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "DEBIAN-CVE-2026-64846",
"summary": "Nix is a package manager for Linux and other Unix systems. Prior to 2.35.0, a malicious derivation executed with the recursive-nix experimental feature can exploit a time-of-check/time-of-use race involving final symlink handling in the LocalStore restore path. The race can cause writeFile to follow a substituted final symlink when opening a path with O_TRUNC instead of enforcing FinalSymlink::DontFollow, allowing the Nix process or nix-daemon to create or truncate an empty file outside the build sandbox with the daemon user's permissions. The primitive does not provide arbitrary-content writes and requires winning the race. This issue is fixed in version 2.35.0.",
"evidence": "osv:DEBIAN-CVE-2026-64846",
"products": [
{
"name": {
"value": "nix",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "2.16.1+dfsg-1",
"evidence": "/affected/0/versions"
},
{
"value": "2.16.1+dfsg-2",
"evidence": "/affected/0/versions"
},
{
"value": "2.16.1+dfsg-3",
"evidence": "/affected/0/versions"
},
{
"value": "2.17.1+dfsg-1",
"evidence": "/affected/0/versions"
},
{
"value": "2.18.1+dfsg-1",
"evidence": "/affected/0/versions"
},
{
"value": "2.22.1+dfsg-1",
"evidence": "/affected/0/versions"
},
{
"value": "2.23.3+dfsg-1",
"evidence": "/affected/0/versions"
},
{
"value": "2.23.3+dfsg-2",
"evidence": "/affected/0/versions"
},
{
"value": "2.24.12+dfsg-1",
"evidence": "/affected/0/versions"
},
{
"value": "2.24.8+dfsg-1",
"evidence": "/affected/0/versions"
},
{
"value": "2.24.9+dfsg-1",
"evidence": "/affected/0/versions"
},
{
"value": "2.24.9+dfsg-2",
"evidence": "/affected/0/versions"
},
{
"value": "2.25.4+dfsg-1",
"evidence": "/affected/0/versions"
},
{
"value": "2.26.3+dfsg-1",
"evidence": "/affected/0/versions"
},
{
"value": "2.32.5+dfsg-1",
"evidence": "/affected/0/versions"
},
{
"value": "2.32.5+dfsg-2",
"evidence": "/affected/0/versions"
},
{
"value": "2.34.3+dfsg-1",
"evidence": "/affected/0/versions"
},
{
"value": "2.34.6+dfsg-1",
"evidence": "/affected/0/versions"
},
{
"value": "2.34.8+dfsg-1",
"evidence": "/affected/0/versions"
},
{
"value": "2.8.0-1.1",
"evidence": "/affected/0/versions"
}
]
},
{
"name": {
"value": "nix",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "2.26.3+dfsg-1",
"evidence": "/affected/1/versions"
},
{
"value": "2.32.5+dfsg-1",
"evidence": "/affected/1/versions"
},
{
"value": "2.32.5+dfsg-2",
"evidence": "/affected/1/versions"
},
{
"value": "2.34.3+dfsg-1",
"evidence": "/affected/1/versions"
},
{
"value": "2.34.6+dfsg-1",
"evidence": "/affected/1/versions"
},
{
"value": "2.34.8+dfsg-1",
"evidence": "/affected/1/versions"
}
]
},
{
"name": {
"value": "nix",
"evidence": "/affected/2/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "2.26.3+dfsg-1",
"evidence": "/affected/2/versions"
},
{
"value": "2.32.5+dfsg-1",
"evidence": "/affected/2/versions"
},
{
"value": "2.32.5+dfsg-2",
"evidence": "/affected/2/versions"
},
{
"value": "2.34.3+dfsg-1",
"evidence": "/affected/2/versions"
},
{
"value": "2.34.6+dfsg-1",
"evidence": "/affected/2/versions"
},
{
"value": "2.34.8+dfsg-1",
"evidence": "/affected/2/versions"
}
]
}
],
"severity": "low",
"structured": {
"id": "DEBIAN-CVE-2026-64846",
"aliases": [
"DEBIAN-CVE-2026-64846"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:N/I:L/A:N"
}
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "nix",
"purl": "pkg:deb/debian/nix?arch=source&distro=bookworm",
"ecosystem": "Debian:12"
},
"versions": [
"2.16.1+dfsg-1",
"2.16.1+dfsg-2",
"2.16.1+dfsg-3",
"2.17.1+dfsg-1",
"2.18.1+dfsg-1",
"2.22.1+dfsg-1",
"2.23.3+dfsg-1",
"2.23.3+dfsg-2",
"2.24.12+dfsg-1",
"2.24.8+dfsg-1",
"2.24.9+dfsg-1",
"2.24.9+dfsg-2",
"2.25.4+dfsg-1",
"2.26.3+dfsg-1",
"2.32.5+dfsg-1",
"2.32.5+dfsg-2",
"2.34.3+dfsg-1",
"2.34.6+dfsg-1",
"2.34.8+dfsg-1",
"2.8.0-1.1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-64846.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "nix",
"purl": "pkg:deb/debian/nix?arch=source&distro=trixie",
"ecosystem": "Debian:13"
},
"versions": [
"2.26.3+dfsg-1",
"2.32.5+dfsg-1",
"2.32.5+dfsg-2",
"2.34.3+dfsg-1",
"2.34.6+dfsg-1",
"2.34.8+dfsg-1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-64846.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "nix",
"purl": "pkg:deb/debian/nix?arch=source&distro=forky",
"ecosystem": "Debian:14"
},
"versions": [
"2.26.3+dfsg-1",
"2.32.5+dfsg-1",
"2.32.5+dfsg-2",
"2.34.3+dfsg-1",
"2.34.6+dfsg-1",
"2.34.8+dfsg-1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-64846.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
}
],
"modified": "2026-10-23T17:47:25.862415025Z",
"provider": "osv",
"upstream": [
"CVE-2026-64846"
],
"references": [
"https://security-tracker.debian.org/tracker/CVE-2026-64846"
]
},
"related_cves": [
{
"value": "CVE-2026-64846",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 416889,
"published_at": "2026-08-20T17:19:16.813+00:00"
}