open_tree_attr: do not allow id-mapping changes without OPEN_TREE_CLONE (CVE-2025-39717) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2025-39717

open_tree_attr: do not allow id-mapping changes without OPEN_TREE_CLONE

Answer in brief

CVE-2025-39717 records a Unknown severity vulnerability in open_tree_attr: do not allow id-mapping changes without OPEN_TREE_CLONE. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 5, 2025Updated Aug 5, 2026Source checked Sep 20, 2026First seen by HOL Aug 5, 2026Material review Aug 5, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Available

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Linux/Linuxgeneric	>=2462651ffa76b87f9c2e4403ef6e6b89b703fb2f <69dbdc711d9130136824e3830191a6afffa0a1f0 \|\| >=2462651ffa76b87f9c2e4403ef6e6b89b703fb2f <9308366f062129d52e0ee3f7a019f7dd41db33df	69dbdc711d9130136824e3830191a6afffa0a1f0, 9308366f062129d52e0ee3f7a019f7dd41db33df
Linux/Linuxgeneric	6.15	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for Linux/Linux, Linux/Linux.
Review the reported fix. Update Linux/Linux to 69dbdc711d9130136824e3830191a6afffa0a1f0 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Sep 5, 2025
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Aug 5, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Aug 5, 2026

Sources and claim methodology

Upstream source description

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.

Quoted source text, attributed separately from HOL analysis.