5.5

CVE-2025-39838: debian debian_linux NULL Pointer Dereference

CVSS: 5.5v3.1MediumModified
AliasesUBUNTU-CVE-2025-39838DEBIAN-CVE-2025-39838
Published 19-09-2025Last modified 12-05-2026
Open JSON

Vulnerability summary

CVE-2025-39838 is a medium (CVSS 5.5) NULL Pointer Dereference vulnerability in debian debian_linux. EPSS estimates a 0.16% chance of exploitation in the next 30 days, higher than 4.8% of scored vulnerabilities.

Overall risk
22/100
0100
Low · default modelHow is this calculated?
CVSS score
5.5/10
010
Medium · v3.1 (NVD)
EPSS score
0.16%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 29 · Related 26
DLA-4328-1DSA-6008-1DSA-6009-1OPENSUSE-SU-2025:20081-1SUSE-SU-2025:03600-1SUSE-SU-2025:03601-1

Timeline

  1. 19-09-2025
    PublishedVulnerability first disclosed.
  2. 12-05-2026
    Last modifiedVulnerability information updated.

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

CVSS metrics

3 scores · 3 sources · 1 version

EPSS trend

Probability

0.16%

Chance of exploitation in the next 30 days

Percentile

5%

Versus all other CVEs

30-day change

0.00 pp

From 0.16% on 19-09-2026

19-09-202619-10-2026
EPSS score
0.16%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Ubuntu149 products
  • linuxAll versions (No fix recorded) | < 6.8.0-106.106
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-awsAll versions (No fix recorded) | < 6.8.0-1050.53
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Debian2 products
  • linux< 6.1.153-1 | < 6.12.48-1 | < 6.16.6-1
  • debian_linuxEOL11.0
Linux2 products
  • linux≥ 41d3f256c6a5e41eb32b87168399c0facd512dc0, < 1f797f062b5cf13a1c2bcc23285361baaa7c9260 | ≥ 41d3f256c6a5e41eb32b87168399c0facd512dc0, < 3c26a8d30ed6b53a52a023ec537dc50a6d34a67a | ≥ 41d3f256c6a5e41eb32b87168399c0facd512dc0, < 70bccd9855dae56942f2b18a08ba137bb54093a0 | 6.12
  • linux_kernel≥ 6.12, < 6.12.46 | ≥ 6.13, < 6.16.6 | 6.17:rc1 | 6.17:rc2 | 6.17:rc3 | 6.17:rc4

3 vendors · 153 products

References

22 links
Show all 22 references