Bug 2516710 (CVE-2026-72136)

Summary: CVE-2026-72136 kernel: xfrm: xfrm_interface: require CAP_NET_ADMIN in the device netns for changelink
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in the Linux kernel's `xfrm_interface` component. A local attacker with specific network administration privileges in one network namespace could exploit this vulnerability to modify the configuration of a network interface in a different network namespace where they are not authorized. This could lead to unauthorized changes to network settings or privilege escalation.
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Description OSIDB Bzimport 2026-08-15 06:27:05 UTC 
In the Linux kernel, the following vulnerability has been resolved:

xfrm: xfrm_interface: require CAP_NET_ADMIN in the device netns for changelink

xfrmi_changelink() operates on at most two netns, dev_net(dev) and the
interface link netns xi->net. They differ once the device is created in
or moved to a netns other than the one the request runs in. The rtnl
changelink path checks CAP_NET_ADMIN only against dev_net(dev), so a
caller privileged there but not in xi->net can rewrite an interface that
lives in xi->net.

Gate xfrmi_changelink() on rtnl_dev_link_net_capable() at its top,
before any attribute is parsed.
Comment 1 Keith Grant 2026-08-17 23:27:50 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026081531-CVE-2026-72136-a058@gregkh/T