6.8

CVE-2025-40268: cifs: client: fix memory leak in smb3_fs_context_parse_param

Deferred
AliasesUBUNTU-CVE-2025-40268DEBIAN-CVE-2025-40268
Published 06-12-2025Last modified 30-10-2026

Vulnerability summary

CVE-2025-40268 is a medium (CVSS 6.8) vulnerability in linux. EPSS estimates a 0.19% chance of exploitation in the next 30 days, higher than 8.4% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 6.8, local access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
6.8/10
010
Medium · v4.0 (OSV · Ubuntu), selected by version preference
EPSS score
0.19%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 29 · Related 27
MGASA-2026-0017MGASA-2026-0018OPENSUSE-SU-2026:20145-1SUSE-SU-2026:0278-1SUSE-SU-2026:0281-1SUSE-SU-2026:0315-1

Timeline

  1. 06-12-2025
    PublishedVulnerability first disclosed.
  2. 30-10-2026
    Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: cifs: client: fix memory leak in smb3_fs_context_parse_param The user calls fsconfig twice, but when the program exits, free() only frees ctx->source for the second fsconfig, not the first. Regarding fc->source, there is no code in the fs context related to its memory reclamation. To fix this memory leak, release the source memory corresponding to ctx or fc before each parsing. syzbot reported: BUG: memory leak unreferenced object 0xffff888128afa360 (size 96): backtrace (crc 79c9c7ba): kstrdup+0x3c/0x80 mm/util.c:84 smb3_fs_context_parse_param+0x229b/0x36c0 fs/smb/client/fs_context.c:1444 BUG: memory leak unreferenced object 0xffff888112c7d900 (size 96): backtrace (crc 79c9c7ba): smb3_fs_context_fullpath+0x70/0x1b0 fs/smb/client/fs_context.c:629 smb3_fs_context_parse_param+0x2266/0x36c0 fs/smb/client/fs_context.c:1438

CVSS metrics

1 score · 1 source · 1 version

EPSS trend

Probability

0.19%

Chance of exploitation in the next 30 days

Percentile

8%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.19% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

No weakness data has been published for this record.

Affected systems

Version check

Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.

Ubuntu154 products
  • linuxAll versions (No fix recorded) | < 6.8.0-106.106 | < 6.17.0-14.14
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-awsAll versions (No fix recorded) | < 6.8.0-1050.53 | < 6.17.0-1007.7
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Debian1 product
  • linuxAll versions (No fix recorded) | < 6.12.63-1 | < 6.17.9-1
Linux1 product
  • linux≥ af1a3d2ba9543e99d78914d8fb88b61d0531d9a1, < 299bc05e1475a4aa1eb985ade8f39e68c1bba9b9 | ≥ af1a3d2ba9543e99d78914d8fb88b61d0531d9a1, < 868fc62811d3fabcf5685e14f36377a855d5412d | ≥ af1a3d2ba9543e99d78914d8fb88b61d0531d9a1, < 48c17341577e25a22feb13d694374b61d974edbc | ≥ af1a3d2ba9543e99d78914d8fb88b61d0531d9a1, < 4515743cc7a42e1d67468402a6420c195532a6fa | ≥ af1a3d2ba9543e99d78914d8fb88b61d0531d9a1, < e8c73eb7db0a498cd4b22d2819e6ab1a6f506bd6 | 5.11

3 vendors · 156 products

References

25 links
Show all 25 references