CVE-2025-39717open_tree_attr: do not allow id-mapping changes without OPEN_TREE_CLONE
Updated under an hour ago ()
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No exploitation reported and no EPSS estimate yet.
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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.
- CVSS
- 7.8 HIGH (v3.1, CNA)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Weakness (CWE)
- Not given
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- Linux
- NVD analysis
- Modified
- Record last updated
- Aug 5, 2026
- First seen by InfoSec Signals
- Oct 19, 2026
Affected products
Linux Linux linux:linux (from the name) | 2462651ffa76b87f9c2e4403ef6e6b89b703fb2f builds before 69dbdc711d9130136824e3830191a6afffa0a1f0; from 2462651ffa76b87f9c2e4403ef6e6b89b703fb2f before 9308366f062129d52e0ee3f7a019f7dd41db33df | CNA record |
linux linux_kernel linux:linux_kernel | from 6.15 before 6.16.4; 6.17; 6.17 | NVD |
References
- https://git.kernel.org/stable/c/69dbdc711d9130136824e3830191a6afffa0a1f0patch
- https://git.kernel.org/stable/c/9308366f062129d52e0ee3f7a019f7dd41db33dfpatch
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.