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NVD / CVE Program· CNA Linux

CVE-2025-68810: KVM: Disallow toggling KVM_MEM_GUEST_MEMFD on an existing memslot

Noroxi assessment

Priority: Monitor (action score 31/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.14% (FIRST EPSS).
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Linux Linux 89dbbe6ff323fc34659621a577fe0af913f47386, 9935df5333aa503a18de5071f53762b65c783c4c, cb51bef465d8ec60a968507330e01020e35dc127.

Low priority for now. Upgrade to Linux Linux 89dbbe6ff323fc34659621a577fe0af913f47386, 9935df5333aa503a18de5071f53762b65c783c4c, cb51bef465d8ec60a968507330e01020e35dc127 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

In the Linux kernel, the following vulnerability has been resolved: KVM: Disallow toggling KVM_MEM_GUEST_MEMFD on an existing memslot Reject attempts to disable KVM_MEM_GUEST_MEMFD on a memslot that was initially created with a guest_memfd binding, as KVM doesn't support toggling KVM_MEM_GUEST_MEMFD on existing memslots. KVM prevents enabling KVM_MEM_GUEST_MEMFD, but doesn't prevent clearing the flag. Failure to reject the new memslot results in a use-after-free due to KVM not unbinding from the guest_memfd instance. Unbinding on a FLAGS_ONLY change is easy enough, and can/will be done as a hardening measure (in anticipation of KVM supporting dirty logging on guest_memfd at some point), but fixing the use-after-free would only address the immediate symptom. ================================================================== BUG: KASAN: slab-use-after-free in kvm_gmem_release+0x362/0x400 [kvm] Write of size 8 at addr ffff8881111ae908 by task repro/745 CPU: 7 UID: 1000 PID: 745 Comm: repro Not tainted 6.18.0-rc6-115d5de2eef3-next-kasan #3 NONE Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 Call Trace: <TASK> dump_stack_lvl+0x51/0x60 print_report+0xcb/0x5c0 kasan_report+0xb4/0xe0 kvm_gmem_release+0x362/0x400 [kvm] __fput+0x2fa/0x9d0 task_work_run+0x12c/0x200 do_exit+0x6ae/0x2100 do_group_exit+0xa8/0x230 __x64_sys_exit_group+0x3a/0x50 x64_sys_call+0x737/0x740 do_syscall_64+0x5b/0x900 entry_SYSCALL_64_after_hwframe+0x4b/0x53 RIP: 0033:0x7f581f2eac31 </TASK> Allocated by task 745 on cpu 6 at 9.746971s: kasan_save_stack+0x20/0x40 kasan_save_track+0x13/0x50 __kasan_kmalloc+0x77/0x90 kvm_set_memory_region.part.0+0x652/0x1110 [kvm] kvm_vm_ioctl+0x14b0/0x3290 [kvm] __x64_sys_ioctl+0x129/0x1a0 do_syscall_64+0x5b/0x900 entry_SYSCALL_64_after_hwframe+0x4b/0x53 Freed by task 745 on cpu 6 at 9.747467s: kasan_save_stack+0x20/0x40 kasan_save_track+0x13/0x50 __kasan_save_free_info+0x37/0x50 __kasan_slab_free+0x3b/0x60 kfree+0xf5/0x440 kvm_set_memslot+0x3c2/0x1160 [kvm] kvm_set_memory_region.part.0+0x86a/0x1110 [kvm] kvm_vm_ioctl+0x14b0/0x3290 [kvm] __x64_sys_ioctl+0x129/0x1a0 do_syscall_64+0x5b/0x900 entry_SYSCALL_64_after_hwframe+0x4b/0x53

HighCVSS 7.8 · v3.1—No exploit Fix available
Published
Jan 13, 2026
Updated
Aug 5, 2026
EPSS
0.1% · 4th percentile
CWE
—

Report tools

JSON

Action score

31

Monitor

Low priority for now.

CVSS
31 / 40 · 7.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

CNA vs NVD score

NVD
—
CNA · Linux
7.8
NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

—

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • 6.8affected
    • a7800aa80ea4d5356b8474c2302812e9d4926fa6 and later · before 89dbbe6ff323fc34659621a577fe0af913f47386affected · git
    • a7800aa80ea4d5356b8474c2302812e9d4926fa6 and later · before cb51bef465d8ec60a968507330e01020e35dc127affected · git
    • a7800aa80ea4d5356b8474c2302812e9d4926fa6 and later · before 9935df5333aa503a18de5071f53762b65c783c4caffected · git
    • before 6.8not affected · semver
    • 6.12.64 and later · up to and including 6.12.*not affected · semver
    • 6.18.3 and later · up to and including 6.18.*not affected · semver
    • 6.19 and laternot affected · original_commit_for_fix

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:13linuxbefore 6.12.69-16.12.69-1
Debian:14linuxbefore 6.18.3-16.18.3-1
openSUSE:Leap 16.0dtb-aarch64before 6.12.0-160000.27.16.12.0-160000.27.1
openSUSE:Leap 16.0kernel-64kbbefore 6.12.0-160000.27.16.12.0-160000.27.1
openSUSE:Leap 16.0kernel-azurebefore 6.12.0-160000.27.16.12.0-160000.27.1
openSUSE:Leap 16.0kernel-defaultbefore 6.12.0-160000.27.16.12.0-160000.27.1
openSUSE:Leap 16.0kernel-default-basebefore 6.12.0-160000.27.1.160000.2.86.12.0-160000.27.1.160000.2.8
openSUSE:Leap 16.0kernel-docsbefore 6.12.0-160000.27.16.12.0-160000.27.1
openSUSE:Leap 16.0kernel-kvmsmallbefore 6.12.0-160000.27.16.12.0-160000.27.1
openSUSE:Leap 16.0kernel-obs-buildbefore 6.12.0-160000.27.16.12.0-160000.27.1
openSUSE:Leap 16.0kernel-obs-qabefore 6.12.0-160000.27.16.12.0-160000.27.1
openSUSE:Leap 16.0kernel-rtbefore 6.12.0-160000.27.16.12.0-160000.27.1
openSUSE:Leap 16.0kernel-sourcebefore 6.12.0-160000.27.16.12.0-160000.27.1
openSUSE:Leap 16.0kernel-symsbefore 6.12.0-160000.27.16.12.0-160000.27.1
openSUSE:Leap 16.0kernel-zfcpdumpbefore 6.12.0-160000.27.16.12.0-160000.27.1
SUSE:Linux Enterprise Live Patching 15 SP7kernel-livepatch-SLE15-SP7_Update_10before 1-150700.15.3.11-150700.15.3.1
SUSE:Linux Enterprise Live Patching 15 SP7kernel-livepatch-SLE15-SP7-RT_Update_10before 1-150700.1.3.11-150700.1.3.1
SUSE:Linux Enterprise Module for Basesystem 15 SP7kernel-64kbbefore 6.4.0-150700.53.34.16.4.0-150700.53.34.1
SUSE:Linux Enterprise Module for Basesystem 15 SP7kernel-defaultbefore 6.4.0-150700.53.34.16.4.0-150700.53.34.1
SUSE:Linux Enterprise Module for Basesystem 15 SP7kernel-default-basebefore 6.4.0-150700.53.34.1.150700.17.23.16.4.0-150700.53.34.1.150700.17.23.1
SUSE:Linux Enterprise Module for Basesystem 15 SP7kernel-sourcebefore 6.4.0-150700.53.34.16.4.0-150700.53.34.1
SUSE:Linux Enterprise Module for Basesystem 15 SP7kernel-zfcpdumpbefore 6.4.0-150700.53.34.16.4.0-150700.53.34.1
SUSE:Linux Enterprise Module for Development Tools 15 SP7kernel-docsbefore 6.4.0-150700.53.34.16.4.0-150700.53.34.1
SUSE:Linux Enterprise Module for Development Tools 15 SP7kernel-obs-buildbefore 6.4.0-150700.53.34.16.4.0-150700.53.34.1

+21

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-74705udp: fix potential use-after-free in tunnel segmentation
    40Plan
  • CVE-2026-74612veth: fix skb length accounting after XDP frag adjustment
    40Plan
  • CVE-2026-74475vxlan: use neigh_ha_snapshot() in route_shortcircuit()
    40Plan

Published before and after this one in the same product

  • ← EarlierCVE-2025-68807Jan 13, 2026 · block: fix race between wbt_enable_default and IO submission
    0Monitor
  • ← EarlierCVE-2025-68808Jan 13, 2026 · media: vidtv: initialize local pointers upon transfer of memory ownership
    31Monitor
  • Later →CVE-2025-68821Jan 13, 2026 · fuse: fix readahead reclaim deadlock
    0Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux89dbbe6ff323fc34659621a577fe0af913f47386Vendor (CNA)
Linux Linux9935df5333aa503a18de5071f53762b65c783c4cVendor (CNA)
Linux Linuxcb51bef465d8ec60a968507330e01020e35dc127Vendor (CNA)
debian:linux6.12.69-1 · Debian:13Package registry (OSV)
opensuse:dtb-aarch646.12.0-160000.27.1 · openSUSE:Leap 16.0Package registry (OSV)
opensuse:kernel-64kb6.12.0-160000.27.1 · openSUSE:Leap 16.0Package registry (OSV)
opensuse:kernel-azure6.12.0-160000.27.1 · openSUSE:Leap 16.0Package registry (OSV)
opensuse:kernel-default6.12.0-160000.27.1 · openSUSE:Leap 16.0Package registry (OSV)
opensuse:kernel-default-base6.12.0-160000.27.1.160000.2.8 · openSUSE:Leap 16.0Package registry (OSV)
opensuse:kernel-docs6.12.0-160000.27.1 · openSUSE:Leap 16.0Package registry (OSV)
opensuse:kernel-kvmsmall6.12.0-160000.27.1 · openSUSE:Leap 16.0Package registry (OSV)
opensuse:kernel-obs-build6.12.0-160000.27.1 · openSUSE:Leap 16.0Package registry (OSV)
opensuse:kernel-obs-qa6.12.0-160000.27.1 · openSUSE:Leap 16.0Package registry (OSV)
opensuse:kernel-rt6.12.0-160000.27.1 · openSUSE:Leap 16.0Package registry (OSV)
opensuse:kernel-source6.12.0-160000.27.1 · openSUSE:Leap 16.0Package registry (OSV)
opensuse:kernel-syms6.12.0-160000.27.1 · openSUSE:Leap 16.0Package registry (OSV)
suse:kernel-64kb6.4.0-150700.53.34.1 · SUSE:Linux Enterprise Module for Basesystem 15 SP7Package registry (OSV)
suse:kernel-default6.4.0-150700.53.34.1 · SUSE:Linux Enterprise Module for Basesystem 15 SP7Package registry (OSV)
suse:kernel-default-base6.4.0-150700.53.34.1.150700.17.23.1 · SUSE:Linux Enterprise Module for Basesystem 15 SP7Package registry (OSV)
suse:kernel-docs6.4.0-150700.53.34.1 · SUSE:Linux Enterprise Module for Development Tools 15 SP7Package registry (OSV)
suse:kernel-livepatch-SLE15-SP7-RT_Update_101-150700.1.3.1 · SUSE:Linux Enterprise Live Patching 15 SP7Package registry (OSV)
suse:kernel-obs-build6.4.0-150700.53.34.1 · SUSE:Linux Enterprise Module for Development Tools 15 SP7Package registry (OSV)
suse:kernel-rt6.4.0-150700.7.34.1 · SUSE:Real Time Module 15 SP7Package registry (OSV)
suse:kernel-source6.4.0-150700.53.34.1 · SUSE:Linux Enterprise Module for Basesystem 15 SP7Package registry (OSV)
suse:kernel-source-rt6.4.0-150700.7.34.1 · SUSE:Real Time Module 15 SP7Package registry (OSV)
suse:kernel-syms6.4.0-150700.53.34.1 · SUSE:Linux Enterprise Module for Development Tools 15 SP7Package registry (OSV)
suse:kernel-syms-rt6.4.0-150700.7.34.1 · SUSE:Real Time Module 15 SP7Package registry (OSV)
suse:kernel-zfcpdump6.4.0-150700.53.34.1 · SUSE:Linux Enterprise Module for Basesystem 15 SP7Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

—

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (2 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records