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TI-2026-46125 Aliases CVE-2026-64561GHSA-hp26-g45f-hxp5

KVM: x86: Check for invalid/obsolete root *after* making MMU pages available

Priority MEDIUM 40CWE-362Published · Updated

Key facts

Attack vector
Local
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
High · High · High
Fix status
Partial Red Hat: 30 fixed, 1 without a fix

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.

Summary

In the Linux kernel, the following vulnerability has been resolved: KVM: x86: Check for invalid/obsolete root *after* making MMU pages available Check for a "stale" page fault, i.e. for an invalid and/or obsolete root, after making MMU pages available for the shadow MMU. If reclaiming shadow pages zaps an in-use root, i.e. marks it invalid, then KVM will attempt to map memory into an invalid root. On its own, populating an invalid root is "fine", but because child shadow pages inherit their parent's role, any children created during the map/fetch will be created as invalid pages, thus violating KVM's invariant that invalid pages are never on the list of active MMU pages. Note, the underlying flaw has existed since KVM first started tracking invalid roots in 2008 (commit 2e53d63acba7, "KVM: MMU: ignore zapped root pagetables"), but the true badness only came along in 2020 (Linux 5.9) with the invariant that invalid shadow pages can't be on the list of active pages. Note #2, inheriting role.invalid when creating child shadow pages is also far from ideal; that flaw will be addressed separately.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00273 19th percentileScored 2026-11-07
Fix Partial Linux (Linux): 5.15.218, 6.1.183, 6.6.148 +4Red Hat: 8 advisoriesRed Hat: 30 fixed, 1 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
LinuxLinux5.9 and later5.15.218, 6.1.183, 6.6.148, 6.12.101, 6.18.42, 7.1.6, 7.2Patch availableCNA
  • Linux VendorLinux Affected 5.9 and later Fixed in 5.15.218, 6.1.183, 6.6.148, 6.12.101, 6.18.42, 7.1.6, 7.2 Patch available CNA

CPE names Threatist (inferred) · 1

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

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

Remediation

  • Fix · CNA Linux (Linux) Fixed in 5.15.218, 6.1.183, 6.6.148, 6.12.101, 6.18.42, 7.1.6, 7.2

Red Hat 8 advisories

  • RHSA-2026:49031 Released 2026-07-31 · Red Hat rating Important
    kernel security, bug fix, and enhancement update
    • Red Hat CodeReady Linux Builder EUS (v.9.6) kernel-tools-libs-devel-5.14.0-570.131.1.el9_6, libperf-5.14.0-570.131.1.el9_6
    • Red Hat Enterprise Linux AppStream EUS (v.9.6) kernel-64k-debug-devel-5.14.0-570.131.1.el9_6, kernel-64k-debug-devel-matched-5.14.0-570.131.1.el9_6, kernel-64k-devel-5.14.0-570.131.1.el9_6 +12
    • Red Hat Enterprise Linux BaseOS EUS (v.9.6) kernel-5.14.0-570.131.1.el9_6, kernel-64k-5.14.0-570.131.1.el9_6, kernel-64k-core-5.14.0-570.131.1.el9_6 +28
    • Red Hat Enterprise Linux Real Time EUS (v.9.6) kernel-rt-5.14.0-570.131.1.el9_6, kernel-rt-64k-5.14.0-570.131.1.el9_6, kernel-rt-64k-core-5.14.0-570.131.1.el9_6 +21
    • Red Hat Enterprise Linux Real Time for NFV EUS (v.9.6) kernel-rt-5.14.0-570.131.1.el9_6, kernel-rt-core-5.14.0-570.131.1.el9_6, kernel-rt-debug-5.14.0-570.131.1.el9_6 +11
  • RHSA-2026:49030 Released 2026-07-31 · Red Hat rating Moderate
    kernel security update
    • Red Hat Enterprise Linux AppStream EUS (v. 10.0) kernel-64k-debug-devel-6.12.0-55.94.1.el10_0, kernel-64k-debug-devel-matched-6.12.0-55.94.1.el10_0, kernel-64k-devel-6.12.0-55.94.1.el10_0 +12
    • Red Hat Enterprise Linux BaseOS EUS (v. 10.0) kernel-6.12.0-55.94.1.el10_0, kernel-64k-6.12.0-55.94.1.el10_0, kernel-64k-core-6.12.0-55.94.1.el10_0 +28
    • Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0) kernel-tools-libs-devel-6.12.0-55.94.1.el10_0, libperf-6.12.0-55.94.1.el10_0
    • Red Hat Enterprise Linux Real Time EUS (v. 10.0) kernel-rt-6.12.0-55.94.1.el10_0, kernel-rt-64k-6.12.0-55.94.1.el10_0, kernel-rt-64k-core-6.12.0-55.94.1.el10_0 +21
    • Red Hat Enterprise Linux Real Time for NFV EUS (v. 10.0) kernel-rt-6.12.0-55.94.1.el10_0, kernel-rt-core-6.12.0-55.94.1.el10_0, kernel-rt-debug-6.12.0-55.94.1.el10_0 +11
  • RHSA-2026:48386 Released 2026-07-31 · Red Hat rating Important
    kernel security update
    • Red Hat Enterprise Linux AppStream E4S (v.9.4) kernel-64k-debug-devel-5.14.0-427.141.1.el9_4, kernel-64k-debug-devel-matched-5.14.0-427.141.1.el9_4, kernel-64k-devel-5.14.0-427.141.1.el9_4 +11
    • Red Hat Enterprise Linux BaseOS E4S (v.9.4) bpftool-7.3.0-427.141.1.el9_4, kernel-5.14.0-427.141.1.el9_4, kernel-64k-5.14.0-427.141.1.el9_4 +29
    • Red Hat Enterprise Linux Real Time E4S (v.9.4) kernel-rt-5.14.0-427.141.1.el9_4, kernel-rt-core-5.14.0-427.141.1.el9_4, kernel-rt-debug-5.14.0-427.141.1.el9_4 +9
    • Red Hat Enterprise Linux Real Time for NFV E4S (v.9.4) kernel-rt-5.14.0-427.141.1.el9_4, kernel-rt-core-5.14.0-427.141.1.el9_4, kernel-rt-debug-5.14.0-427.141.1.el9_4 +11
Show 5 more Red Hat advisories
  • RHSA-2026:47869 Released 2026-07-29 · Red Hat rating Important
    kernel security update
    • Red Hat Enterprise Linux BaseOS E4S (v.8.8) bpftool-4.18.0-477.156.1.el8_8, kernel-4.18.0-477.156.1.el8_8, kernel-abi-stablelists-4.18.0-477.156.1.el8_8 +14
    • Red Hat Enterprise Linux BaseOS TUS (v.8.8) bpftool-4.18.0-477.156.1.el8_8, kernel-4.18.0-477.156.1.el8_8, kernel-abi-stablelists-4.18.0-477.156.1.el8_8 +14
  • RHSA-2026:45192 Released 2026-07-24 · Red Hat rating Important
    kernel security, bug fix, and enhancement update
    • Red Hat Enterprise Linux AppStream (v. 9) kernel-64k-debug-devel-5.14.0-687.30.1.el9_8, kernel-64k-debug-devel-matched-5.14.0-687.30.1.el9_8, kernel-64k-devel-5.14.0-687.30.1.el9_8 +12
    • Red Hat Enterprise Linux BaseOS (v. 9) kernel-5.14.0-687.30.1.el9_8, kernel-64k-5.14.0-687.30.1.el9_8, kernel-64k-core-5.14.0-687.30.1.el9_8 +28
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) kernel-tools-libs-devel-5.14.0-687.30.1.el9_8, libperf-5.14.0-687.30.1.el9_8
    • Red Hat Enterprise Linux Real Time (v. 9) kernel-rt-5.14.0-687.30.1.el9_8, kernel-rt-64k-5.14.0-687.30.1.el9_8, kernel-rt-64k-core-5.14.0-687.30.1.el9_8 +21
    • Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt-5.14.0-687.30.1.el9_8, kernel-rt-core-5.14.0-687.30.1.el9_8, kernel-rt-debug-5.14.0-687.30.1.el9_8 +9
  • RHSA-2026:45114 Released 2026-07-24 · Red Hat rating Important
    kernel security update
    • Red Hat Enterprise Linux AppStream (v. 10) kernel-64k-debug-devel-6.12.0-211.39.1.el10_2, kernel-64k-debug-devel-matched-6.12.0-211.39.1.el10_2, kernel-64k-devel-6.12.0-211.39.1.el10_2 +12
    • Red Hat Enterprise Linux BaseOS (v. 10) kernel-6.12.0-211.39.1.el10_2, kernel-64k-6.12.0-211.39.1.el10_2, kernel-64k-core-6.12.0-211.39.1.el10_2 +29
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) kernel-tools-libs-devel-6.12.0-211.39.1.el10_2, libperf-6.12.0-211.39.1.el10_2
    • Red Hat Enterprise Linux Real Time (v. 10) kernel-rt-6.12.0-211.39.1.el10_2, kernel-rt-64k-6.12.0-211.39.1.el10_2, kernel-rt-64k-core-6.12.0-211.39.1.el10_2 +21
    • Red Hat Enterprise Linux Real Time for NFV (v. 10) kernel-rt-6.12.0-211.39.1.el10_2, kernel-rt-core-6.12.0-211.39.1.el10_2, kernel-rt-debug-6.12.0-211.39.1.el10_2 +9
  • RHSA-2026:45115 Released 2026-07-24 · Red Hat rating Important
    kernel security update
    • Red Hat Enterprise Linux BaseOS (v. 8) bpftool-4.18.0-553.147.1.el8_10, kernel-4.18.0-553.147.1.el8_10, kernel-abi-stablelists-4.18.0-553.147.1.el8_10 +19
    • Red Hat Enterprise Linux CRB (v. 8) kernel-tools-libs-devel-4.18.0-553.147.1.el8_10
  • RHSA-2026:45116 Released 2026-07-24 · Red Hat rating Important
    kernel-rt security update
    • Red Hat Enterprise Linux NFV (v. 8) kernel-rt-4.18.0-553.147.1.rt7.488.el8_10, kernel-rt-core-4.18.0-553.147.1.rt7.488.el8_10, kernel-rt-debug-4.18.0-553.147.1.rt7.488.el8_10 +9
    • Red Hat Enterprise Linux RT (v. 8) kernel-rt-4.18.0-553.147.1.rt7.488.el8_10, kernel-rt-core-4.18.0-553.147.1.rt7.488.el8_10, kernel-rt-debug-4.18.0-553.147.1.rt7.488.el8_10 +7

Vendor assessments

Red Hat

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

ProductStatusPlan or fix
Red Hat Enterprise Linux 9AffectedNo fix yet
Red Hat CodeReady Linux Builder EUS (v.9.6)Fixed RHSA-2026:49031
Red Hat Enterprise Linux AppStream (v. 10)Fixed RHSA-2026:45114
Red Hat Enterprise Linux AppStream (v. 9)Fixed RHSA-2026:45192
Red Hat Enterprise Linux AppStream E4S (v.9.4)Fixed RHSA-2026:48386
Red Hat Enterprise Linux AppStream EUS (v. 10.0)Fixed RHSA-2026:49030
Red Hat Enterprise Linux AppStream EUS (v.9.6)Fixed RHSA-2026:49031
Red Hat Enterprise Linux BaseOS (v. 10)Fixed RHSA-2026:45114
Red Hat Enterprise Linux BaseOS (v. 8)Fixed RHSA-2026:45115
Red Hat Enterprise Linux BaseOS (v. 9)Fixed RHSA-2026:45192
Red Hat Enterprise Linux BaseOS E4S (v.8.8)Fixed RHSA-2026:47869
Red Hat Enterprise Linux BaseOS E4S (v.9.4)Fixed RHSA-2026:48386
Red Hat Enterprise Linux BaseOS EUS (v. 10.0)Fixed RHSA-2026:49030
Red Hat Enterprise Linux BaseOS EUS (v.9.6)Fixed RHSA-2026:49031
Red Hat Enterprise Linux BaseOS TUS (v.8.8)Fixed RHSA-2026:47869
Red Hat Enterprise Linux CRB (v. 8)Fixed RHSA-2026:45115
Red Hat Enterprise Linux CodeReady Linux Builder (v. 10)Fixed RHSA-2026:45114
Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)Fixed RHSA-2026:45192
Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0)Fixed RHSA-2026:49030
Red Hat Enterprise Linux NFV (v. 8)Fixed RHSA-2026:45116
Red Hat Enterprise Linux RT (v. 8)Fixed RHSA-2026:45116
Red Hat Enterprise Linux Real Time (v. 10)Fixed RHSA-2026:45114
Red Hat Enterprise Linux Real Time (v. 9)Fixed RHSA-2026:45192
Red Hat Enterprise Linux Real Time E4S (v.9.4)Fixed RHSA-2026:48386
Red Hat Enterprise Linux Real Time EUS (v. 10.0)Fixed RHSA-2026:49030
Red Hat Enterprise Linux Real Time EUS (v.9.6)Fixed RHSA-2026:49031
Red Hat Enterprise Linux Real Time for NFV (v. 10)Fixed RHSA-2026:45114
Red Hat Enterprise Linux Real Time for NFV (v. 9)Fixed RHSA-2026:45192
Red Hat Enterprise Linux Real Time for NFV E4S (v.9.4)Fixed RHSA-2026:48386
Red Hat Enterprise Linux Real Time for NFV EUS (v. 10.0)Fixed RHSA-2026:49030
Red Hat Enterprise Linux Real Time for NFV EUS (v.9.6)Fixed RHSA-2026:49031
Not affected: 2 products
  • Red Hat Enterprise Linux 6
  • Red Hat Enterprise Linux 7

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-64561
  2. 2026-10-03 Alias added: GHSA-hp26-g45f-hxp5
  3. 2026-10-16 CISA SSVC decision points changed
  4. 2026-10-16 Priority changed: LOW → MEDIUM
  5. 2026-10-20 Weakness changed · CISA ADP

References

Other 8

  • 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