CVE-2025-38736: Linux kernel · net: usb: asix_devices: Fix PHY address mask in MDIO bus initialization
Affects Linux kernelSource CVE Database V5
Not known to be exploited · fixed in fcb4ce9f729c1d08e53abf9d449340e24c3edee6 : update Linux kernel when convenient.
Data as of 10 Nov 2026, 12:50 UTC
Rated Medium by Threat Radar's AI analysis · No CVSS score from NVD or the CNA
Thin evidence
One scorer or none- Patch
- Available – fixed in fcb4ce9f729c1d08e53abf9d449340e24c3edee6, 22042ffedd8c2c6db08ccdd6d4273068eddd3c5c, 748da80831221ae24b4bc8d7ffb22acd5712a341 +6
Exploitation evidence
Disclosed: evidence found.
CVE published 5 Sep 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 10 Nov 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in
|
AI-suggested
A fix is available and included in Linux kernel versions 6.12.44, 6.16, and 6.16.4. Users and administrators should update affected Linux kernel versions to these fixed releases to remediate the vulnerability.
Description
A vulnerability in the Linux kernel's USB ASIX device driver was fixed by properly masking the PHY address during MDIO bus initialization. The issue involved a shift-out-of-bounds exception caused by using unmasked PHY addresses, which should be limited to 5 bits (0-31). This flaw could lead to invalid PHY addresses being used, potentially disrupting MDIO bus operations. The fix ensures the PHY address is masked with 0x1f to keep it within the valid range.
References
- git.kernel.org/stable/c/fcb4ce9f729c1d08e53abf9d449340e24c3edee6 (opens in a new tab)
- git.kernel.org/stable/c/8f141f2a4f2ef8ca865d5921574c3d6535e00a49 (opens in a new tab)
- git.kernel.org/stable/c/748da80831221ae24b4bc8d7ffb22acd5712a341 (opens in a new tab)
- git.kernel.org/stable/c/22042ffedd8c2c6db08ccdd6d4273068eddd3c5c (opens in a new tab)
- git.kernel.org/stable/c/523eab02fce458fa6d3c51de5bb055800986953e (opens in a new tab)
- git.kernel.org/stable/c/24ef2f53c07f273bad99173e27ee88d44d135b1c (opens in a new tab)
- lists.debian.org/debian-lts-announce/2025/10/msg00008.html (opens in a new tab)
- cert-portal.siemens.com/productcert/html/ssa-032379.html (opens in a new tab)
- cert-portal.siemens.com/productcert/html/ssa-019113.html (opens in a new tab)
- cert-portal.siemens.com/productcert/html/ssa-457936.html (opens in a new tab)