CVE-2025-37947 [High] | Out-of-bounds Write in Linux Kernel

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.

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2025-10-16	0.05%	0.04%	-0.01%
2	2025-09-19	0.02%	0.05%	+0.03%
3	2025-05-21	—	0.02%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2025-10-16

0.05%

0.04%

-0.01%

2025-09-19

0.02%

0.05%

+0.03%

2025-05-21

—

0.02%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
7.8	3.1	HIGH	`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H` Click to expand Attack vector (AV:L) They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by. Attack complexity (AC:L) Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup. Privileges required (PR:L) A normal user session is enough; they don’t have to be admin. User interaction (UI:N) Nobody has to click “OK” or open a trap file; it can work without a victim helping. Scope (S:U) Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems. Confidentiality (C:H) Serious risk that confidential data gets exposed in a big way. Integrity (I:H) They could widely tamper with or forge data—trust in the data is badly hurt. Availability (A:H) Could take the service down hard or make it unusable for people who depend on it.	1.8	5.9	[email protected]
7.8	3.1	HIGH	`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H` Click to expand Attack vector (AV:L) They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by. Attack complexity (AC:L) Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup. Privileges required (PR:L) A normal user session is enough; they don’t have to be admin. User interaction (UI:N) Nobody has to click “OK” or open a trap file; it can work without a victim helping. Scope (S:U) Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems. Confidentiality (C:H) Serious risk that confidential data gets exposed in a big way. Integrity (I:H) They could widely tamper with or forge data—trust in the data is badly hurt. Availability (A:H) Could take the service down hard or make it unusable for people who depend on it.	1.8	5.9	134c704f-9b21-4f2e-91b3-4a467353bcc0

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

7.8

3.1

HIGH

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Click to expand

Attack vector (AV:L): They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L): Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L): A normal user session is enough; they don’t have to be admin.
User interaction (UI:N): Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U): Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H): Serious risk that confidential data gets exposed in a big way.
Integrity (I:H): They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H): Could take the service down hard or make it unusable for people who depend on it.

1.8

5.9

[email protected]

7.8

3.1

HIGH

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Click to expand

Attack vector (AV:L): They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L): Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L): A normal user session is enough; they don’t have to be admin.
User interaction (UI:N): Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U): Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H): Serious risk that confidential data gets exposed in a big way.
Integrity (I:H): They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H): Could take the service down hard or make it unusable for people who depend on it.

1.8

5.9

134c704f-9b21-4f2e-91b3-4a467353bcc0

OS Trackers for CVE-2025-37947

vendor	priority	summary	link
`debian`	unimportant	CVE-2025-37947 unimportant priority: Debian including 2 source packages (linux, linux-6.1), 6 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 6.	https://security-tracker.debian.org/tracker/CVE-2025-37947
`redhat`	—	—	https://access.redhat.com/security/cve/CVE-2025-37947
`suse`	medium	CVE-2025-37947 severity moderate: SUSE including 26 source package names (cluster-md-kmp-default, dlm-kmp-default, …), 244 product×package rows across 48 product lines (SLES-LTSS-TERADATA 15 SP2, SUSE Linux Enterprise High Availability Extension 15 SP7, … (48 product lines)): Known Not Affected 244.	https://www.suse.com/security/cve/CVE-2025-37947/
`ubuntu`	medium	CVE-2025-37947 medium priority: Ubuntu including 158 source packages (linux, linux-allwinner-5.19, …), 1551 status rows across 10 suites (bionic, focal, jammy, noble, oracular, plucky, questing, trusty, upstream, xenial): DNE 1145, ignored 168, released 136, needed 77, not-affected 22, needs-triage 2, pending 1.	https://ubuntu.com/security/CVE-2025-37947

Affected software / configurations for CVE-2025-37947

Vendor	Product	Version	Raw CPE
linux	linux_kernel	>= 5.15, < 6.1.139	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 6.2, < 6.6.91	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 6.7, < 6.12.29	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 6.13, < 6.14.7	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	6.15	cpe:2.3:o:linux:linux_kernel:6.15:rc1::::::
linux	linux_kernel	6.15	cpe:2.3:o:linux:linux_kernel:6.15:rc2::::::
linux	linux_kernel	6.15	cpe:2.3:o:linux:linux_kernel:6.15:rc3::::::
linux	linux_kernel	6.15	cpe:2.3:o:linux:linux_kernel:6.15:rc4::::::
linux	linux_kernel	6.15	cpe:2.3:o:linux:linux_kernel:6.15:rc5::::::
debian	debian_linux	11.0	cpe:2.3:o:debian:debian_linux:11.0:::::::*

References for CVE-2025-37947

URL	Tags
https://git.kernel.org/stable/c/04c8a38c60346bb5a7c49b276de7233f703ce9cb	Patch
https://git.kernel.org/stable/c/0ca6df4f40cf4c32487944aaf48319cb6c25accc	Patch
https://git.kernel.org/stable/c/7f61da79df86fd140c7768e668ad846bfa7ec8e1	Patch
https://git.kernel.org/stable/c/d62ba16563a86aae052f96d270b3b6f78fca154c	Patch
https://git.kernel.org/stable/c/e6356499fd216ed6343ae0363f4c9303f02c5034	Patch
https://lists.debian.org/debian-lts-announce/2025/08/msg00010.html	Third Party Advisory Mailing List
https://github.com/doyensec/KSMBD-CVE-2025-37947/blob/main/CVE-2025-37947.c	Third Party Advisory Mailing List

URL

CVE-2025-37947 | ksmbd: prevent out-of-bounds stream writes by validating *pos

Exploit prediction scoring system (EPSS) score for CVE-2025-37947

Common vulnerability scoring system (CVSS) metrics for CVE-2025-37947

Weakness enumeration for CVE-2025-37947

OS Trackers for CVE-2025-37947

Affected software / configurations for CVE-2025-37947

References for CVE-2025-37947