7.5

CVE-2023-3866: ksmbd: validate session id and tree id in the compound request

Modified
AliasesUBUNTU-CVE-2023-3866DEBIAN-CVE-2023-3866
Published 16-08-2025Last modified 05-08-2026

Vulnerability summary

CVE-2023-3866 is a high (CVSS 7.5) NULL Pointer Dereference vulnerability in linux. EPSS estimates a 12.22% chance of exploitation in the next 30 days, higher than 96.1% of scored vulnerabilities.

Priority
Prioritisesevere

Severe, CVSS 7.5 (CVE.org); no exploitation reported by the 5 checked sources; EPSS 12% (FIRST, 03-11-2026)

Source freshness unavailable

How is this decided?
CVSS score
7.5/10
010
High · v3.1 (CVE.org)
EPSS score
12.22%
0%100%
Medium · +1.15 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 8 · Related 8
USN-6416-1USN-6416-2USN-6416-3USN-6445-1USN-6445-2USN-6464-1

Timeline

  1. 16-08-2025
    PublishedVulnerability first disclosed.
  2. 05-08-2026
    Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: ksmbd: validate session id and tree id in the compound request This patch validate session id and tree id in compound request. If first operation in the compound is SMB2 ECHO request, ksmbd bypass session and tree validation. So work->sess and work->tcon could be NULL. If secound request in the compound access work->sess or tcon, It cause NULL pointer dereferecing error.

CVSS metrics

5 scores · 4 sources · 2 versions

EPSS trend

Probability

12.22%

Chance of exploitation in the next 30 days

Percentile

96%

Versus all other CVEs

30-day change

Increase +1.15 pp

From 11.07% 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

Affected systems

Version check

Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.

Ubuntu91 products
  • linux< 5.15.0-86.96
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-aws< 5.15.0-1047.52
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Linux2 products
  • linux≥ 0626e6641f6b467447c81dd7678a69c66f7746cf, < eb947403518ea3d93f6d89264bb1f5416bb0c7d0 | ≥ 0626e6641f6b467447c81dd7678a69c66f7746cf, < 854156d12caa9d36de1cf5f084591c7686cc8a9d | ≥ 0626e6641f6b467447c81dd7678a69c66f7746cf, < d1066c1b3663401cd23c0d6e60cdae750ce00c0f | ≥ 0626e6641f6b467447c81dd7678a69c66f7746cf, < 5005bcb4219156f1bf7587b185080ec1da08518e | 5.15
  • linux_kernel≥ 5.15, < 5.15.121 | ≥ 5.16, < 6.1.36 | ≥ 6.2, < 6.3.10 | 6.4:rc1 | 6.4:rc2 | 6.4:rc3 | 6.4:rc4 | 6.4:rc5 | 6.4:rc6 | 6.4:rc7
Debian1 product
  • linux< 6.1.37-1 | < 6.3.11-1

3 vendors · 94 products

References

17 links
Show all 17 references