userns and mnt_idmap leak in open_tree_attr(2)
Priority LOW 24Published · Updated
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Partial Red Hat: 1 without a fix
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat.
Summary
In the Linux kernel, the following vulnerability has been resolved: userns and mnt_idmap leak in open_tree_attr(2) Once want_mount_setattr() has returned a positive, it does require finish_mount_kattr() to release ->mnt_userns. Failing do_mount_setattr() does not change that. As the result, we can end up leaking userns and possibly mnt_idmap as well.
Why it matters now
EPSS 0.0014 3rd percentileScored 2026-11-07
Fix Partial Linux (Linux): 6.15.5, 6.16Red Hat: 1 without a fix
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Linux | Linux | 6.15 and later | 6.15.5, 6.16 | Patch available | CNA |
- Linux VendorLinux Affected 6.15 and later Fixed in 6.15.5, 6.16 Patch available CNA
CPE configurations NVD · 4
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | 6.15 to before 6.15.5 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.16:rc1:*:*:*:*:*:* | 6.16 rc1 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.16:rc2:*:*:*:*:*:* | 6.16 rc2 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.16:rc3:*:*:*:*:*:* | 6.16 rc3 | Vulnerable | Linux |
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 6.15 to before 6.15.5 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.16:rc1:*:*:*:*:*:* Versions 6.16 rc1 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.16:rc2:*:*:*:*:*:* Versions 6.16 rc2 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.16:rc3:*:*:*:*:*:* Versions 6.16 rc3 Vulnerable ·Linux
Remediation
- Fix · CNA Linux (Linux) Fixed in 6.15.5, 6.16
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Out of support scope |
Not affected: 4 products
- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
Timeline
- 2026-10-02 Threatist record created from CVE-2025-38247
- 2026-10-03 Alias added: GHSA-3w4f-86g3-p6vp
References
More Linux Kernel vulnerabilities
- TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
- TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
- TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
- TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
- TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
- TI-2021-05514 Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE KEVCVSS 3.1HIGH 8.3
Sources
- CVE-2025-38247 · CVE Program
- CVE-2025-38247 · NVD
- FIRST EPSS
- GHSA-3w4f-86g3-p6vp · GitHub Advisory Database · CC BY 4.0
- CVE-2025-38247 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences