System crash via stale ERSPAN netns entry
Published May 28, 2026 · Updated May 28, 2026
Use-after-free in Linux Kernel 4.16.12 through 4.17 allows local users to crash the kernel through an IPv6 ERSPAN network-namespace migration. ip6erspan_changelink() uses dev_net(dev) instead of cached t->net after IFLA_NET_NS_FD migration, reinserting the tunnel into the wrong per-netns hash and leaving a stale entry. An unprivileged user namespace is sufficient to reach the flaw; namespace teardown dereferences the stale entry, triggers a kernel BUG, and crashes the system.
Summary
What happened
Use-after-free in Linux Kernel 4.16.12 through 4.17 allows local users to crash the kernel through an IPv6 ERSPAN network-namespace migration. ip6erspan_changelink() uses dev_net(dev) instead of cached t->net after IFLA_NET_NS_FD migration, reinserting the tunnel into the wrong per-netns hash and leaving a stale entry. An unprivileged user namespace is sufficient to reach the flaw; namespace teardown dereferences the stale entry, triggers a kernel BUG, and crashes the system.
The record
- CVE
- CVE-2026-46120
- Published
- May 28, 2026
- Updated
- May 28, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux Kernel
- Classifications
- CWE-416, T1499.004
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- May 28, 2026CVE publishedPublication date reported by the CVE source.
- May 28, 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?
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- Affected versionversion=2d665034f239412927b1e71329f20f001c92da09 <1d324c2f43f70c965f25c58cc3611c779adbe47e
- Affected versionversion=2d665034f239412927b1e71329f20f001c92da09 <311fdd26eb4443d43b909cc67a10f3a5fd1b21b2
- Affected versionversion=2d665034f239412927b1e71329f20f001c92da09 <cf7fc624329e76c6394653d12353e1d033adea91
- Affected versionversion=2d665034f239412927b1e71329f20f001c92da09 <e70cfb40c3a99b232cd42c6a6a10f0d8e039dc82
- Affected versionversion=2d665034f239412927b1e71329f20f001c92da09 <eca62bb0569de4d43a4dac06a2092a9d4ca1d702
- Affected versionversion=4.16.12 <4.17
- Affected versionversion=4.17
- Affected versionversion=c6d72628352c949629af619b77b042e0fb5245e7
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
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Public exploit references
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Technologies
Your stack
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Your stack
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