TI-2026-75916 Aliases CVE-2026-98788 GHSA-qwmc-gmgx-xf8h

Linux futex private hash use-after-free on resize

LOW 22Published 2026-10-18 · Updated 2026-10-19

Key facts

Attack vector: —
Privileges required: —
User interaction: —
Attack complexity: —
Impact type: —
Confidentiality · integrity · availability: —
Fix status: Partial Red Hat: 1 without a fix

No CVSS vector from any source. Fix status from CNA and Red Hat.

Summary

The Linux kernel futex subsystem has a use-after-free in private hash handling during resize, because __futex_pivot_hash() sets the grace-period batches before it replaces the hash pointer. If a new RCU grace period starts between those two assignments, futex_ref_drop() can advance while a reader still holds a pointer to the old hash. Linux is affected from 6.17, and Red Hat rates the issue Moderate with no fix available for Red Hat Enterprise Linux 10. CISA has not added it to KEV.

Written with Claude Haiku 5.5 from the sources below · 2026-11-06

Description from the CNA

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.

Why it matters now

EPSS 0.00155 4th percentileScored 2026-11-07

Fix Partial Linux (Linux): 7.2.10, 7.3Red Hat: 1 without a fix

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
Linux	Linux	6.17 and later	7.2.10, 7.3	Patch available	CNA

Linux VendorLinux Affected 6.17 and later Fixed in 7.2.10, 7.3 Patch available CNA

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPE	Versions	Role	Vendor
cpe:2.3:o:linux:linux_kernel::::::::	—	—	Linux

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions — — ·Linux

Remediation

Upgrade to Linux kernel 7.2.10 or 7.3, which set the batches after assigning the hash pointer and remove the unneeded scoped_guard(rcu). Red Hat Enterprise Linux 10 has no fix available yet.

Written with Claude Haiku 5.5 from the sources below · 2026-11-06

Fix · CNA Linux (Linux) Fixed in 7.2.10, 7.3

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

Product	Status	Plan or fix
Red Hat Enterprise Linux 10	Affected	No fix yet: Fix deferred

Timeline

2026-10-18 Threatist record created from CVE-2026-98788
2026-10-18 Alias added: GHSA-qwmc-gmgx-xf8h
2026-10-19 Fix available: Linux/[email protected] · CNA
2026-10-21 Affected versions changed · Red Hat
2026-10-21 CVSS score added · Red Hat

References

Other 2

TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
TI-2021-02452 Incorrect authorization in Ubuntu linux kernel KEVCVSS 3.1HIGH 8.8
TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4

See all 21741 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences