System crash via stale MPLS header offset
Published Sep 25, 2026 · Updated Sep 25, 2026
Denial of service in the Linux kernel MPLS path allows attackers to crash affected systems through MPLS push, pop, and recirculation. skb_mpls_pop() leaves inner_protocol and inner_network_header stale after the last label is removed; ovs_fragment() later widens the resulting negative header offset into a roughly 4 GiB memcpy length. Triggering the fault requires an Open vSwitch flow that removes all MPLS labels, recirculates the packet, reapplies MPLS, and reaches fragmentation; the observed consequence is a kernel page fault and system crash.
Summary
What happened
Denial of service in the Linux kernel MPLS path allows attackers to crash affected systems through MPLS push, pop, and recirculation. skb_mpls_pop() leaves inner_protocol and inner_network_header stale after the last label is removed; ovs_fragment() later widens the resulting negative header offset into a roughly 4 GiB memcpy length. Triggering the fault requires an Open vSwitch flow that removes all MPLS labels, recirculates the packet, reapplies MPLS, and reaches fragmentation; the observed consequence is a kernel page fault and system crash.
The record
- CVE
- CVE-2026-97612
- Published
- Sep 25, 2026
- Updated
- Sep 25, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- T1499.004
- Attack vector
- Unavailable
- Privileges
- Unavailable
Timeline
How it unfolded
- Sep 25, 2026CVE publishedPublication date reported by the CVE source.
- Sep 25, 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=48d2ab609b6bbecb7698487c8579bc40de9d6dfa <011e17b5cae19b9f6a150923275e41c278de64f0
- Affected versionversion=48d2ab609b6bbecb7698487c8579bc40de9d6dfa <78a86d75a70e1e227711c72865c59b1422d0a5ae
- Affected versionversion=48d2ab609b6bbecb7698487c8579bc40de9d6dfa <b39120523475d6b436be7f6cb27d48064148a327
- Affected versionversion=48d2ab609b6bbecb7698487c8579bc40de9d6dfa <da8c3a7f5d3137fec4ff60a6248f5f6d66b6a63e
- Affected versionversion=4.9
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Activity data is delayed. The latest report is Sep 28, 2026.
Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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