TI-2025-26512 Aliases CVE-2025-39838 GHSA-9q78-c4fv-64q9

cifs: prevent NULL pointer dereference in UTF16 conversion

LOW 24CWE-476Published 2025-09-19 · Updated 2026-11-05

Key facts

Attack vector: Local
Privileges required: Low
User interaction: None
Attack complexity: Low
Impact type: Denial of service
Confidentiality · integrity · availability: None · None · High
Fix status: Partial Red Hat: 3 without a fix

Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat. Impact type from CWE-476.

Summary

In the Linux kernel, the following vulnerability has been resolved: cifs: prevent NULL pointer dereference in UTF16 conversion There can be a NULL pointer dereference bug here. NULL is passed to __cifs_sfu_make_node without checks, which passes it unchecked to cifs_strndup_to_utf16, which in turn passes it to cifs_local_to_utf16_bytes where '*from' is dereferenced, causing a crash. This patch adds a check for NULL 'src' in cifs_strndup_to_utf16 and returns NULL early to prevent dereferencing NULL pointer. Found by Linux Verification Center (linuxtesting.org) with SVACE

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.0016 5th percentileScored 2026-11-07

Fix Partial Linux (Linux): 6.12.46, 6.16.6, 6.17Red Hat: 3 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: No
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
Linux	Linux	6.12 and later	6.12.46, 6.16.6, 6.17	Patch available	CNA

Linux VendorLinux Affected 6.12 and later Fixed in 6.12.46, 6.16.6, 6.17 Patch available CNA

CPE configurations NVD · 6

CPE	Versions	Role	Vendor
cpe:2.3:o:linux:linux_kernel::::::::	6.12 to before 6.12.46; 6.13 to before 6.16.6	Vulnerable	Linux
cpe:2.3:o:linux:linux_kernel:6.17:rc1::::::	6.17 rc1	Vulnerable	Linux
cpe:2.3:o:linux:linux_kernel:6.17:rc2::::::	6.17 rc2	Vulnerable	Linux
cpe:2.3:o:linux:linux_kernel:6.17:rc3::::::	6.17 rc3	Vulnerable	Linux
cpe:2.3:o:linux:linux_kernel:6.17:rc4::::::	6.17 rc4	Vulnerable	Linux
cpe:2.3:o:debian:debian_linux:11.0:::::::*	11.0	Vulnerable	Debian

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 6.12 to before 6.12.46; 6.13 to before 6.16.6 Vulnerable ·Linux
cpe:2.3:o:linux:linux_kernel:6.17:rc1:*:*:*:*:*:* Versions 6.17 rc1 Vulnerable ·Linux
cpe:2.3:o:linux:linux_kernel:6.17:rc2:*:*:*:*:*:* Versions 6.17 rc2 Vulnerable ·Linux
cpe:2.3:o:linux:linux_kernel:6.17:rc3:*:*:*:*:*:* Versions 6.17 rc3 Vulnerable ·Linux
cpe:2.3:o:linux:linux_kernel:6.17:rc4:*:*:*:*:*:* Versions 6.17 rc4 Vulnerable ·Linux
cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:* Versions 11.0 Vulnerable ·Debian

Remediation

Fix · CNA Linux (Linux) Fixed in 6.12.46, 6.16.6, 6.17

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

Product	Status	Plan or fix
Red Hat Enterprise Linux 10	Affected	No fix yet: Fix deferred
Red Hat Enterprise Linux 8	Affected	No fix yet: Fix deferred
Red Hat Enterprise Linux 9	Affected	No fix yet: Fix deferred

Not affected: 2 products

Red Hat Enterprise Linux 6
Red Hat Enterprise Linux 7

Timeline

2026-10-02 Threatist record created from CVE-2025-39838
2026-10-03 Alias added: GHSA-9q78-c4fv-64q9
2026-11-05 CISA SSVC decision points changed

References

Patch 3

Advisory 1

https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html

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

See all 15278 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences