cbcvebase.
CVE-2025-39717
published 2025-09-05

CVE-2025-39717: In the Linux kernel, the following vulnerability has been resolved: open_tree_attr: do not allow id-mapping changes without OPEN_TREE_CLONE As described in…

PriorityP340high7.8CVSS 3.1
AVLACLPRLUINSUCHIHAH
EPSS
0.14%
3.9th percentile
In the Linux kernel, the following vulnerability has been resolved: open_tree_attr: do not allow id-mapping changes without OPEN_TREE_CLONE As described in commit 7a54947e727b ('Merge patch series "fs: allow changing idmappings"'), open_tree_attr(2) was necessary in order to allow for a detached mount to be created and have its idmappings changed without the risk of any racing threads operating on it. For this reason, mount_setattr(2) still does not allow for id-mappings to be changed. However, there was a bug in commit 2462651ffa76 ("fs: allow changing idmappings") which allowed users to bypass this restriction by calling open_tree_attr(2) *without* OPEN_TREE_CLONE. can_idmap_mount() prevented this bug from allowing an attached mountpoint's id-mapping from being modified (thanks to an is_anon_ns() check), but this still allows for detached (but visible) mounts to have their be id-mapping changed. This risks the same UAF and locking issues as described in the merge commit, and was likely unintentional.

Affected

7 ranges
VendorProductVersion rangeFixed in
debianlinux< linux 6.16.5-1 (forky)linux 6.16.5-1 (forky)
linuxlinux——
linuxlinux>= 2462651ffa76b87f9c2e4403ef6e6b89b703fb2f < 69dbdc711d9130136824e3830191a6afffa0a1f069dbdc711d9130136824e3830191a6afffa0a1f0
linuxlinux>= 2462651ffa76b87f9c2e4403ef6e6b89b703fb2f < 9308366f062129d52e0ee3f7a019f7dd41db33df9308366f062129d52e0ee3f7a019f7dd41db33df
linuxlinux_kernel——
linuxlinux_kernel>= 0 < 6.16.5-16.16.5-1
linuxlinux_kernel>= 6.15 < 6.16.46.16.4

CVSS provenance

nvdv3.17.8HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
osv7.8HIGH
vendor_debian7.8LOW
vendor_redhat7.8HIGH
Stop checking back — get the weekly exploitation signal.

Every Monday: what got weaponized or added to CISA KEV in the last seven days — each CVE cross-linked to its PoC, Nuclei template, and detection rule. Free, one email a week, unsubscribe in one click.