ksmbd: prevent out-of-bounds stream writes by validating *pos
Priority HIGH 73CWE-787Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-787 and the CVSS impact.
Summary
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.
Why it matters now
Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00657 51st percentileScored 2026-11-07
Fix Fixed Linux (Linux): 6.1.139, 6.6.91, 6.12.29 +2
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Linux | Linux | 5.15 and later | 6.1.139, 6.6.91, 6.12.29, 6.14.7, 6.15 | Patch available | CNA |
- Linux VendorLinux Affected 5.15 and later Fixed in 6.1.139, 6.6.91, 6.12.29, 6.14.7, 6.15 Patch available CNA
CPE configurations NVD · 7
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | 5.15 to before 6.1.139; 6.2 to before 6.6.91; 6.7 to before 6.12.29; 6.13 to before 6.14.7 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.15:rc1:*:*:*:*:*:* | 6.15 rc1 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.15:rc2:*:*:*:*:*:* | 6.15 rc2 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.15:rc3:*:*:*:*:*:* | 6.15 rc3 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.15:rc4:*:*:*:*:*:* | 6.15 rc4 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.15:rc5:*:*:*:*:*:* | 6.15 rc5 | Vulnerable | Linux |
| cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:* | 11.0 | Vulnerable | Debian |
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 5.15 to before 6.1.139; 6.2 to before 6.6.91; 6.7 to before 6.12.29; 6.13 to before 6.14.7 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.15:rc1:*:*:*:*:*:* Versions 6.15 rc1 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.15:rc2:*:*:*:*:*:* Versions 6.15 rc2 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.15:rc3:*:*:*:*:*:* Versions 6.15 rc3 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.15:rc4:*:*:*:*:*:* Versions 6.15 rc4 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.15:rc5:*:*:*:*:*:* Versions 6.15 rc5 Vulnerable ·Linux
- cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:* Versions 11.0 Vulnerable ·Debian
Remediation
- Fix · CNA Linux (Linux) Fixed in 6.1.139, 6.6.91, 6.12.29, 6.14.7, 6.15
Vendor assessments
Red Hat
Red Hat rating: Low. Red Hat's page for this CVE →
Not affected: 5 products
- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
Timeline
- 2026-10-02 Threatist record created from CVE-2025-37947
- 2026-10-03 Alias added: GHSA-c42x-xw5m-9j9p
- 2026-10-16 EPSS moved to the 50th–90th percentile
- 2026-11-07 Affected versions changed · Red Hat
References
Patch 5
- https://git.kernel.org/stable/c/7f61da79df86fd140c7768e668ad846bfa7ec8e1
- https://git.kernel.org/stable/c/04c8a38c60346bb5a7c49b276de7233f703ce9cb
- https://git.kernel.org/stable/c/d62ba16563a86aae052f96d270b3b6f78fca154c
- https://git.kernel.org/stable/c/e6356499fd216ed6343ae0363f4c9303f02c5034
- https://git.kernel.org/stable/c/0ca6df4f40cf4c32487944aaf48319cb6c25accc
More Linux Kernel vulnerabilities
- TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
- TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
- TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
- TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
- TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
- TI-2021-05514 Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE KEVCVSS 3.1HIGH 8.3
Sources
- CVE-2025-37947 · CVE Program
- CVE-2025-37947 · NVD
- FIRST EPSS
- GHSA-c42x-xw5m-9j9p · GitHub Advisory Database · CC BY 4.0
- CVE-2025-37947 · Red Hat security data · CC BY 4.0
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