CVE-2025-21910: Linux kernel · wifi: cfg80211: regulatory: improve invalid hints checking
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 5.5 Medium · fixed in 5.4.0-1146.156~18.04.1 : update Linux kernel when convenient.
Data as of 28 Oct 2026, 12:58 UTC
- Patch
- Available – fixed in 5.4.0-1146.156~18.04.1, 5.4.0-1151.158~18.04.1, 5.4.0-1149.158~18.04.1 +89
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 1 Apr 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: 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 26 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Patches and advisories
- ubuntu.com/security/notices/USN-7510-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7510-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7511-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7511-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7512-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7516-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7516-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7517-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7518-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7510-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7510-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-7510-5 (opens in a new tab)
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 24.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-azure-6.11pkg:deb/ubuntu/linux-azure-6.11?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-azure-nvidiapkg:deb/ubuntu/linux-azure-nvidia?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A patch is available and has been incorporated into multiple fixed Linux kernel versions, including various 5.4.x and 5.15.x releases. Users should update their Linux kernel to one of the fixed versions listed to remediate this issue. After updating, a system reboot is required to apply the changes. No additional mitigation steps are necessary as the fix fully addresses the invalid regulatory hint processing.
Description
CVE-2025-21910 is a vulnerability in the Linux kernel's wifi regulatory subsystem where invalid regulatory hints containing non-latin alphabetic characters can bypass existing checks. This flaw arises because the kernel's validation function incorrectly accepts non-latin letters as valid country codes, leading to malformed regulatory domain data and kernel warnings. The issue has been fixed by enhancing the validation to strictly allow only latin letters in regulatory hints.
References
- ubuntu.com/security/CVE-2025-21910 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2025-21910 (opens in a new tab)
- git.kernel.org/linus/59b348be7597c4a9903cb003c69e37df20c04a30 (opens in a new tab)
- git.kernel.org/stable/c/17aa34c84867f6cd181a5743e1c647e7766962a6 (opens in a new tab)
- git.kernel.org/stable/c/35ef07112b61b06eb30683a6563c9f6378c02476 (opens in a new tab)
- git.kernel.org/stable/c/59b348be7597c4a9903cb003c69e37df20c04a30 (opens in a new tab)
- git.kernel.org/stable/c/62b1a9bbfebba4b4c2bb6c1ede9ef7ecee7a9ff6 (opens in a new tab)
- git.kernel.org/stable/c/6a5e3b23054cee3b92683d1467e3fa83921f5622 (opens in a new tab)
- git.kernel.org/stable/c/be7c5f00aa7f1344293e4d48d0e12be83a2f223d (opens in a new tab)
- git.kernel.org/stable/c/da3f599517ef2ea851208df3229d07728d238dc5 (opens in a new tab)
- git.kernel.org/stable/c/f4112cb477c727a65787a4065a75ca593bb5b2f4 (opens in a new tab)
- ubuntu.com/security/notices/USN-7510-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7510-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7511-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7511-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7512-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7516-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7516-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7517-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7518-1 (opens in a new tab)