CVE-2026-63955
In the Linux kernel, the following vulnerability has been resolved: mm/vmalloc: do not trigger BUG() on BH disabled context __get_vm_area_node() currently triggers a BUG() if in_interrupt() returns true. However, in_interrupt() also reports true when BH are disabled. The bridge code can call rhashtable_lookup_insert_fast() with bottom halves disabled: __vlan_add() -> br_fdb_add_local() spin_lock_bh(&br->hash_lock); <-- Disable BH -> fdb_add_local() -> fdb_create() -> rhashtable_lookup_insert_fast() -> kvmalloc() -> vmalloc() -> __get_vm_area_node() -> BUG_ON(in_interrupt()) spin_unlock_bh(&br->hash_lock) this triggers the BUG() despite the caller not being in NMI or hard IRQ context. Replace the in_interrupt() check with in_nmi() || in_hardirq().
Affected versions
Linux kernel versions
6.19
and later are affected. Fixed in
7.0.12,
7.1
and their respective stable series.
References
2 totalFrequently asked questions
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What is CVE-2026-63955?
CVE-2026-63955 is a unscored severity Linux kernel vulnerability . It affects Linux kernel versions from 6.19 onward and has been patched in 7.0.12 and 7.1. CVE-2026-63955 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
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Is there a patch available for CVE-2026-63955?
Yes — CVE-2026-63955 has been patched. Fixed versions include 7.0.12 and 7.1. If you are running Linux kernel 6.19 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2026-63955 actively exploited?
No — CVE-2026-63955 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.