CVE-2026-98788
In the Linux kernel, the following vulnerability has been resolved: futex: Fix private hash use-after-free on resize poll_state_synchronize_rcu(mm->futex.phash.batches) is used by futex_ref_drop() to check that a grace period has passed since the current hash was published. This relies on batches referencing a grace period which started after the hash pointer was assigned. __futex_pivot_hash() sets mmph->batches before it replaces mmph->hash: scoped_guard(rcu) { mmph->batches = get_state_synchronize_rcu(); rcu_assign_pointer(mmph->hash, new); } The scoped_guard(rcu) doesn't stop new grace periods from starting, and if one starts between those two assignments, futex_ref_drop() can move forward while a reader still holds a pointer to the old hash. Fix things by setting mmph->batches after assigning mmph->hash. The scoped_guard(rcu) isn't needed, so let's drop that as well.
Affected versions
Linux kernel versions
6.17
and later are affected. Fixed in
7.2.10,
7.3
and their respective stable series.
References
2 totalFrequently asked questions
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What is CVE-2026-98788?
CVE-2026-98788 is a unscored severity Linux kernel vulnerability . It affects Linux kernel versions from 6.17 onward and has been patched in 7.2.10 and 7.3. CVE-2026-98788 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-2026-98788?
Yes. CVE-2026-98788 has been patched. Fixed versions include 7.2.10 and 7.3. If you are running Linux kernel 6.17 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2026-98788 actively exploited?
No. CVE-2026-98788 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.