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NVD / CVE Program· CNA Linux

CVE-2025-68171: x86/fpu: Ensure XFD state on signal delivery

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: 0.15% (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 1811c610653c0cd21cc9add14595b7cffaeca511, 388eff894d6bc5f921e9bfff0e4b0ab2684a96e9, 3f735419c4b43cde42e6d408db39137b82474e31.

Low priority for now. Upgrade to Linux Linux 1811c610653c0cd21cc9add14595b7cffaeca511, 388eff894d6bc5f921e9bfff0e4b0ab2684a96e9, 3f735419c4b43cde42e6d408db39137b82474e31 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: x86/fpu: Ensure XFD state on signal delivery Sean reported [1] the following splat when running KVM tests: WARNING: CPU: 232 PID: 15391 at xfd_validate_state+0x65/0x70 Call Trace: <TASK> fpu__clear_user_states+0x9c/0x100 arch_do_signal_or_restart+0x142/0x210 exit_to_user_mode_loop+0x55/0x100 do_syscall_64+0x205/0x2c0 entry_SYSCALL_64_after_hwframe+0x4b/0x53 Chao further identified [2] a reproducible scenario involving signal delivery: a non-AMX task is preempted by an AMX-enabled task which modifies the XFD MSR. When the non-AMX task resumes and reloads XSTATE with init values, a warning is triggered due to a mismatch between fpstate::xfd and the CPU's current XFD state. fpu__clear_user_states() does not currently re-synchronize the XFD state after such preemption. Invoke xfd_update_state() which detects and corrects the mismatch if there is a dynamic feature. This also benefits the sigreturn path, as fpu__restore_sig() may call fpu__clear_user_states() when the sigframe is inaccessible. [ dhansen: minor changelog munging ]

HighCVSS 7.8 · v3.1—No exploit Fix available
Published
Dec 16, 2025
Updated
Oct 15, 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%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

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.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

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When you'll hear from us

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  • when exploit code appears or is weaponized
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  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

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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

    • 5.16affected
    • 672365477ae8afca5a1cca98c1deb733235e4525 and later · before eefbfb722042fc9210d2e0ac2b063fd1abf51895affected · git
    • 672365477ae8afca5a1cca98c1deb733235e4525 and later · before 1811c610653c0cd21cc9add14595b7cffaeca511affected · git
    • 672365477ae8afca5a1cca98c1deb733235e4525 and later · before 5b2619b488f1d08b960c43c6468dd0759e8b3035affected · git
    • 672365477ae8afca5a1cca98c1deb733235e4525 and later · before 3f735419c4b43cde42e6d408db39137b82474e31affected · git
    • 672365477ae8afca5a1cca98c1deb733235e4525 and later · before 388eff894d6bc5f921e9bfff0e4b0ab2684a96e9affected · git
    • before 5.16not affected · semver
    • 6.1.159 and later · up to and including 6.1.*not affected · semver
    • 6.6.117 and later · up to and including 6.6.*not affected · semver
    • 6.12.58 and later · up to and including 6.12.*not affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.159-16.1.159-1
Debian:13linuxbefore 6.12.63-16.12.63-1
Debian:14linuxbefore 6.17.8-16.17.8-1

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-2025-68169Dec 16, 2025 · netpoll: Fix deadlock in memory allocation under spinlock
    0Monitor
  • ← EarlierCVE-2025-68170Dec 16, 2025 · drm/radeon: Do not kfree() devres managed rdev
    31Monitor
  • Later →CVE-2025-68172Dec 16, 2025 · crypto: aspeed - fix double free caused by devm
    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 Linux1811c610653c0cd21cc9add14595b7cffaeca511Vendor (CNA)
Linux Linux388eff894d6bc5f921e9bfff0e4b0ab2684a96e9Vendor (CNA)
Linux Linux3f735419c4b43cde42e6d408db39137b82474e31Vendor (CNA)
Linux Linux5b2619b488f1d08b960c43c6468dd0759e8b3035Vendor (CNA)
Linux Linuxeefbfb722042fc9210d2e0ac2b063fd1abf51895Vendor (CNA)
debian:linux6.1.159-1 · Debian:12Package 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. SSVC exploitation— → none
  2. Fix✗ → ✓

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

References

Show all references (4 more)

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

All records