ALPINE-CVE-2026-78409
The X-mount.subdir option uses a detached-tree fast path on Linux 6.15 and later and passes the configured subdirectory to open_tree() with AT_SYMLINK_NOFOLLOW. That flag does not stop intermediate symlink traversal or keep resolution inside the newly mounted filesystem. A local unprivileged user with an fstab-authorized X-mount.subdir entry can attach a host path at the intended mountpoint.
ALPINE-CVE-2026-78409
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: osv:ALPINE-CVE-2026-78409
util-linux
Source reference: /affected/0/package/name
- Affected versions
- Not stated in this record
- Fixed versions
- 2.42.3-r0
Source reference:
/affected/0/ranges - Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "2.42.3-r0"
}
]
}
],
"package": {
"name": "util-linux",
"purl": "pkg:apk/alpine/util-linux?arch=source",
"ecosystem": "Alpine:v3.24"
},
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2026-78409.json"
},
"ecosystem_specific": {}
}
]Publisher severity
No explicit severity was provided.
- Event
- #55175 · Revision 1
- Added to Heist Feed
- Publisher date