Log in Start free

Vulnerability · Published Sep 19, 2025 · Assigned by Linux

CVE-2025-39838cifs: prevent NULL pointer dereference in UTF16 conversion

Medium 5.5

In plain English

A medium-severity security flaw in Linux from Linux. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 5% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS NVD)5.5Medium
Exploit odds (30 days)0.2%top 94.7% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official description

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

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12linux6.1.153-1DEBIAN-CVE-2025-39838
Debian:13linux6.12.48-1DEBIAN-CVE-2025-39838
Debian:14linux6.16.6-1DEBIAN-CVE-2025-39838
Ubuntu:24.04:LTSlinux6.8.0-106.106USN-8095-1
Ubuntu:22.04:LTSlinux-allwinner-5.19no fix listedUBUNTU-CVE-2025-39838
Ubuntu:24.04:LTSlinux-aws6.8.0-1050.53USN-8095-1
Ubuntu:22.04:LTSlinux-aws-5.19no fix listedUBUNTU-CVE-2025-39838
Ubuntu:24.04:LTSlinux-aws-6.14no fix listedUBUNTU-CVE-2025-39838
Ubuntu:22.04:LTSlinux-aws-6.2no fix listedUBUNTU-CVE-2025-39838
Ubuntu:22.04:LTSlinux-aws-6.5no fix listedUBUNTU-CVE-2025-39838
Ubuntu:22.04:LTSlinux-aws-6.86.8.0-1050.53~22.04.1USN-8095-4
Ubuntu:24.04:LTSlinux-azure6.8.0-1051.57USN-8125-1
Ubuntu:22.04:LTSlinux-azure-5.19no fix listedUBUNTU-CVE-2025-39838
Ubuntu:24.04:LTSlinux-azure-6.11no fix listedUBUNTU-CVE-2025-39838
Ubuntu:24.04:LTSlinux-azure-6.14no fix listedUBUNTU-CVE-2025-39838
Ubuntu:22.04:LTSlinux-azure-6.2no fix listedUBUNTU-CVE-2025-39838
Ubuntu:22.04:LTSlinux-azure-6.5no fix listedUBUNTU-CVE-2025-39838
Ubuntu:25.10linux-azure-fdeno fix listedUBUNTU-CVE-2025-39838
Ubuntu:22.04:LTSlinux-azure-fde-5.19no fix listedUBUNTU-CVE-2025-39838
Ubuntu:24.04:LTSlinux-azure-fde-6.14no fix listedUBUNTU-CVE-2025-39838
Ubuntu:22.04:LTSlinux-azure-fde-6.2no fix listedUBUNTU-CVE-2025-39838
Ubuntu:24.04:LTSlinux-azure-nvidia-6.14no fix listedUBUNTU-CVE-2025-39838
Ubuntu:24.04:LTSlinux-gcp6.8.0-1052.55USN-8095-1
Ubuntu:22.04:LTSlinux-gcp-5.19no fix listedUBUNTU-CVE-2025-39838
Ubuntu:24.04:LTSlinux-gcp-6.11no fix listedUBUNTU-CVE-2025-39838
Ubuntu:24.04:LTSlinux-gcp-6.14no fix listedUBUNTU-CVE-2025-39838
Ubuntu:22.04:LTSlinux-gcp-6.2no fix listedUBUNTU-CVE-2025-39838
Ubuntu:22.04:LTSlinux-gcp-6.5no fix listedUBUNTU-CVE-2025-39838
Ubuntu:22.04:LTSlinux-gcp-6.86.8.0-1052.55~22.04.1USN-8095-1
Ubuntu:24.04:LTSlinux-gke6.8.0-1048.53USN-8095-1
Ubuntu:24.04:LTSlinux-gkeop6.8.0-1035.38USN-8095-1
Ubuntu:22.04:LTSlinux-hwe-5.19no fix listedUBUNTU-CVE-2025-39838
Ubuntu:24.04:LTSlinux-hwe-6.11no fix listedUBUNTU-CVE-2025-39838
Ubuntu:24.04:LTSlinux-hwe-6.14no fix listedUBUNTU-CVE-2025-39838
Ubuntu:22.04:LTSlinux-hwe-6.2no fix listedUBUNTU-CVE-2025-39838
Ubuntu:22.04:LTSlinux-hwe-6.5no fix listedUBUNTU-CVE-2025-39838
Ubuntu:22.04:LTSlinux-hwe-6.86.8.0-106.106~22.04.1USN-8095-1
Ubuntu:24.04:LTSlinux-ibm6.8.0-1049.49USN-8095-1
Ubuntu:22.04:LTSlinux-ibm-6.86.8.0-1049.49~22.04.1USN-8095-1
Ubuntu:24.04:LTSlinux-intelno fix listedUBUNTU-CVE-2025-39838
Ubuntu:22.04:LTSlinux-intel-iot-realtimeno fix listedUBUNTU-CVE-2025-39838
Ubuntu:24.04:LTSlinux-lowlatency6.8.0-106.106.1USN-8095-1
Ubuntu:22.04:LTSlinux-lowlatency-hwe-5.19no fix listedUBUNTU-CVE-2025-39838
Ubuntu:24.04:LTSlinux-lowlatency-hwe-6.11no fix listedUBUNTU-CVE-2025-39838
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.2no fix listedUBUNTU-CVE-2025-39838
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.5no fix listedUBUNTU-CVE-2025-39838
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.86.8.0-106.106.1~22.04.1USN-8095-1
Ubuntu:24.04:LTSlinux-nvidia6.8.0-1049.52USN-8100-1
Ubuntu:24.04:LTSlinux-nvidia-6.11no fix listedUBUNTU-CVE-2025-39838
Ubuntu:22.04:LTSlinux-nvidia-6.2no fix listedUBUNTU-CVE-2025-39838
Ubuntu:22.04:LTSlinux-nvidia-6.5no fix listedUBUNTU-CVE-2025-39838
Ubuntu:22.04:LTSlinux-nvidia-6.86.8.0-1049.52~22.04.1USN-8100-1
Ubuntu:24.04:LTSlinux-nvidia-lowlatency6.8.0-1049.52.1USN-8100-1
Ubuntu:22.04:LTSlinux-oem-5.17no fix listedUBUNTU-CVE-2025-39838
Ubuntu:22.04:LTSlinux-oem-6.0no fix listedUBUNTU-CVE-2025-39838
Ubuntu:22.04:LTSlinux-oem-6.1no fix listedUBUNTU-CVE-2025-39838
Ubuntu:24.04:LTSlinux-oem-6.11no fix listedUBUNTU-CVE-2025-39838
Ubuntu:24.04:LTSlinux-oem-6.14no fix listedUBUNTU-CVE-2025-39838
Ubuntu:22.04:LTSlinux-oem-6.5no fix listedUBUNTU-CVE-2025-39838
Ubuntu:24.04:LTSlinux-oem-6.8no fix listedUBUNTU-CVE-2025-39838
Ubuntu:24.04:LTSlinux-oracle6.8.0-1047.48USN-8095-1
Ubuntu:24.04:LTSlinux-oracle-6.14no fix listedUBUNTU-CVE-2025-39838
Ubuntu:22.04:LTSlinux-oracle-6.5no fix listedUBUNTU-CVE-2025-39838
Ubuntu:22.04:LTSlinux-oracle-6.86.8.0-1047.48~22.04.1USN-8095-1
Ubuntu:24.04:LTSlinux-raspi6.8.0-1050.54USN-8095-5
Ubuntu:24.04:LTSlinux-raspi-realtimeno fix listedUBUNTU-CVE-2025-39838
Ubuntu:22.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2025-39838
Ubuntu:24.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2025-39838
Ubuntu:22.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2025-39838
Ubuntu:24.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2025-39838
Ubuntu:22.04:LTSlinux-riscv-5.19no fix listedUBUNTU-CVE-2025-39838
Ubuntu:24.04:LTSlinux-riscv-6.14no fix listedUBUNTU-CVE-2025-39838
Ubuntu:22.04:LTSlinux-riscv-6.5no fix listedUBUNTU-CVE-2025-39838
Ubuntu:22.04:LTSlinux-starfive-5.19no fix listedUBUNTU-CVE-2025-39838
Ubuntu:22.04:LTSlinux-starfive-6.2no fix listedUBUNTU-CVE-2025-39838
Ubuntu:22.04:LTSlinux-starfive-6.5no fix listedUBUNTU-CVE-2025-39838
Ubuntu:24.04:LTSlinux-xilinx6.8.0-1029.30USN-8261-1

Affected products (as reported)

VendorProductVersions
Linux Linux 41d3f256c6a5e41eb32b87168399c0facd512dc0 – before 1f797f062b5cf13a1c2bcc23285361baaa7c926041d3f256c6a5e41eb32b87168399c0facd512dc0 – before 3c26a8d30ed6b53a52a023ec537dc50a6d34a67a41d3f256c6a5e41eb32b87168399c0facd512dc0 – before 70bccd9855dae56942f2b18a08ba137bb54093a0
Linux Linux 6.12

References