Staging Environment: Content and features may be unstable or change without notice.
Advisory details: ubuntu_osv / UBUNTU-CVE-2025-39926
Advisory ID ubuntu_osv/UBUNTU-CVE-2025-39926
Aliases CVE-2025-39926
Summary In the Linux kernel, the following vulnerability has been resolved: genetlink: fix genl_bind() invoking bind() after -EPERM Per family bind/unbind callbacks were introduced to allow families to track multicast group consumer presence, e.g. to start or stop producing events depending on listeners. However, in genl_bind() the bind() callback was invoked even if capability checks failed and ret was set to -EPERM. This means that callbacks could run on behalf of unauthorized callers while the syscall still returned failure to user space. Fix this by only invoking bind() after "if (ret) break;" check i.e. after permission checks have succeeded.
Status Published
Exploitability 0.5
Weighted Severity 6.2
Risk 3.1
Affected and Fixed Packages Package Details
Introduced and Fixed Package Commit Patches Package Commit Patches Details
Weaknesses (0)
There are no known CWE.
System Score Found at
cvssv3.1 5.5 https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2025/UBUNTU-CVE-2025-39926.json
ubuntu-priority medium https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2025/UBUNTU-CVE-2025-39926.json
Reference id Reference type URL
https://git.kernel.org/linus/1dbfb0363224f6da56f6655d596dc5097308d6f5
https://ubuntu.com/security/CVE-2025-39926
https://www.cve.org/CVERecord?id=CVE-2025-39926
1dbfb0363224f6da56f6655d596dc5097308d6f5 Other https://git.kernel.org/stable/c/1dbfb0363224f6da56f6655d596dc5097308d6f5
8858c1e9405906c09589d7c336f04058ea198207 Other https://git.kernel.org/stable/c/8858c1e9405906c09589d7c336f04058ea198207
98c9d884047a3051c203708914a874dece3cbe54 Other https://git.kernel.org/stable/c/98c9d884047a3051c203708914a874dece3cbe54
No exploits are available.

No EPSS data available for this advisory.

Patch URL
There are no known patches.
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Found at https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2025/UBUNTU-CVE-2025-39926.json
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none

There are no SSVC decisions available.