CVE-2025-37947

ksmbd: prevent out-of-bounds stream writes by validating *pos

HIGH
7.8
CVSS Score
Published: May 20, 2025 at 04:01 PM UTC
Updated: August 5, 2026 at 12:44 PM UTC
2 products affected across 2 vendorsLinux KernelDebian Linux

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Severity
HIGH7.8
Exploit prediction
EPSS 0.7%
SSVC
PoC

Description

In the Linux kernel, the following vulnerability has been resolved: ksmbd: prevent out-of-bounds stream writes by validating *pos ksmbd_vfs_stream_write() did not validate whether the write offset (*pos) was within the bounds of the existing stream data length (v_len). If *pos was greater than or equal to v_len, this could lead to an out-of-bounds memory write. This patch adds a check to ensure *pos is less than v_len before proceeding. If the condition fails, -EINVAL is returned.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

5.15 ≤ v < 6.1.1395.15 ≤ v < 6.12.295.15 ≤ v < 6.14.75.15 ≤ v < 6.155.15 ≤ v < 6.6.916.13 ≤ v < 6.14.76.2 ≤ v < 6.6.916.7 ≤ v < 6.12.296.15 rc16.15 rc26.15 rc36.15 rc46.15 rc5626e6641f6b467447c81dd7678a69c66f7746cf
Vendor states this is fixed in 04c8a38c60346bb5a7c49b276de7233f703ce9cb (fixed)
Vendor states this is fixed in 0ca6df4f40cf4c32487944aaf48319cb6c25accc (fixed)
Vendor states this is fixed in 7f61da79df86fd140c7768e668ad846bfa7ec8e1 (fixed)
Vendor states this is fixed in d62ba16563a86aae052f96d270b3b6f78fca154c (fixed)
Vendor states this is fixed in e6356499fd216ed6343ae0363f4c9303f02c5034 (fixed)
Vendor states this is fixed in 5.15 (unaffected)
Vendor states this is fixed in 6.1.139 (unaffected)
Vendor states this is fixed in 6.12.29 (unaffected)
Vendor states this is fixed in 6.14.7 (unaffected)
Vendor states this is fixed in 6.15 (unaffected)
Vendor states this is fixed in 6.6.91 (unaffected)

References (7)

Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/04c8a38c60346bb5a7c49b276de7233f703ce9cb
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/0ca6df4f40cf4c32487944aaf48319cb6c25accc
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/7f61da79df86fd140c7768e668ad846bfa7ec8e1
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/d62ba16563a86aae052f96d270b3b6f78fca154c
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/e6356499fd216ed6343ae0363f4c9303f02c5034
Mailing ListThird Party Advisory
Source: af854a3a-2127-422b-91ae-364da2661108
https://lists.debian.org/debian-lts-announce/2025/08/msg00010.html
Mailing ListThird Party Advisory
Source: 134c704f-9b21-4f2e-91b3-4a467353bcc0
https://github.com/doyensec/KSMBD-CVE-2025-37947/blob/main/CVE-2025-37947.c

SSVC — Action Prioritization

SSVCPoCNot automatableTotal impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.8HIGHCISA-ADP
Attack Vector
LOCAL
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-787

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