Cross-namespace tunnel modification via incorrect capability check
Published Aug 15, 2026 · Updated Aug 15, 2026
Authorization bypass in affected Linux kernel releases allows local users to modify SIT tunnels across network namespaces through rtnetlink. The ipip6_changelink() path checks CAP_NET_ADMIN only in dev_net(dev) before applying attributes to a tunnel whose link namespace t->net can differ. Exploitation requires local CAP_NET_ADMIN in the device namespace, but permits tunnel endpoint, routing, and 6rd changes in another namespace, enabling traffic redirection or sustained connectivity loss.
Summary
What happened
Authorization bypass in affected Linux kernel releases allows local users to modify SIT tunnels across network namespaces through rtnetlink. The ipip6_changelink() path checks CAP_NET_ADMIN only in dev_net(dev) before applying attributes to a tunnel whose link namespace t->net can differ. Exploitation requires local CAP_NET_ADMIN in the device namespace, but permits tunnel endpoint, routing, and 6rd changes in another namespace, enabling traffic redirection or sustained connectivity loss.
The record
- CVE
- CVE-2026-72061
- Published
- Aug 15, 2026
- Updated
- Aug 15, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- CWE-266, T1068
- Attack vector
- local
- Privileges
- Unavailable
Timeline
How it unfolded
- Aug 15, 2026CVE publishedPublication date reported by the CVE source.
- Aug 15, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=3.11
- Affected versionversion=5e6700b3bf98fe98d630bf9c939ad4c85ce95592 <27ccb68e7cccead5d8c611665a45d23032d468b3
- Affected versionversion=5e6700b3bf98fe98d630bf9c939ad4c85ce95592 <3118e97dae533fb45964b87bbed1801afcff7c65
- Affected versionversion=5e6700b3bf98fe98d630bf9c939ad4c85ce95592 <388ccffbd2e7e5e4271f291085a7451865705305
- Affected versionversion=5e6700b3bf98fe98d630bf9c939ad4c85ce95592 <7d139dec96691cde96cb40ed293e2d13d994fb4f
- Affected versionversion=5e6700b3bf98fe98d630bf9c939ad4c85ce95592 <99ae3248b33df94201915d9c32e7470cdf08cfcd
- Affected versionversion=5e6700b3bf98fe98d630bf9c939ad4c85ce95592 <c0ea1aedb37bb979e864ed7787975434bbd9db73
- Affected versionversion=5e6700b3bf98fe98d630bf9c939ad4c85ce95592 <c5a0ae895432596b2f464172da8218e2d84e2932
- Affected versionversion=5e6700b3bf98fe98d630bf9c939ad4c85ce95592 <cb41b308e9d867725d965b291dd085028e36a480
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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