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NVD / CVE Program· CNA Linux

CVE-2025-21863: io_uring: prevent opcode speculation

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: 0.26% (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 18eae8420081ef8e043ad455937bfb470ef08607, 1e988c3fe1264708f4f92109203ac5b1d65de50b, 506b9b5e8c2d2a411ea8fe361333f5081c56d23a; azl3 kernel 6.6.78.1-3 on Azure Linux 3.0 6.6.82.1-1; azl3 kernel 6.6.82.1-1 on Azure Linux 3.0 6.6.82.1-1.

Low priority for now. Upgrade to Linux Linux 18eae8420081ef8e043ad455937bfb470ef08607, 1e988c3fe1264708f4f92109203ac5b1d65de50b, 506b9b5e8c2d2a411ea8fe361333f5081c56d23a; azl3 kernel 6.6.78.1-3 on Azure Linux 3.0 6.6.82.1-1; azl3 kernel 6.6.82.1-1 on Azure Linux 3.0 6.6.82.1-1 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: io_uring: prevent opcode speculation sqe->opcode is used for different tables, make sure we santitise it against speculations.

HighCVSS 7.8 · v3.1—No exploit Fix available
Published
Mar 12, 2025
Updated
Oct 15, 2026
EPSS
0.2% · 19th 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 · 0.2%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
7.8
CNA · Linux
7.8
agree

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

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2025-21863

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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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.

VendorProduct
linuxlinux kernel

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • linux linux kernel5.6 and later · before 6.6.80
  • linux linux kernel6.7 and later · before 6.12.17
  • linux linux kernel6.13 and later · before 6.13.5
  • linux linux kernel6.14

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

    • 5.6affected
    • d3656344fea0339fb0365c8df4d2beba4e0089cd and later · before 87e9eef43c758da267f6332678058a79764c7ebaaffected · git
    • d3656344fea0339fb0365c8df4d2beba4e0089cd and later · before 18eae8420081ef8e043ad455937bfb470ef08607affected · git
    • d3656344fea0339fb0365c8df4d2beba4e0089cd and later · before d261ead565a080e3411b0dd04e6d58a52471cac8affected · git
    • d3656344fea0339fb0365c8df4d2beba4e0089cd and later · before b9826e3b26ec031e9063f64a7c735449c43955e4affected · git
    • d3656344fea0339fb0365c8df4d2beba4e0089cd and later · before 506b9b5e8c2d2a411ea8fe361333f5081c56d23aaffected · git
    • d3656344fea0339fb0365c8df4d2beba4e0089cd and later · before fdbfd52bd8b85ed6783365ff54c82ab7067bd61baffected · git
    • d3656344fea0339fb0365c8df4d2beba4e0089cd and later · before 1e988c3fe1264708f4f92109203ac5b1d65de50baffected · git
    • before 5.6not affected · semver
    • 5.10.259 and later · up to and including 5.10.*not affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.176-16.1.176-1
Debian:13linuxbefore 6.12.17-16.12.17-1
Red Hat:rhel_eus:9.6::appstreamkernel-64k-debug-debuginfobefore 0:5.14.0-570.84.1.el9_60:5.14.0-570.84.1.el9_6
Red Hat:rhel_eus:9.6::appstreamkernel-64k-debug-develbefore 0:5.14.0-570.84.1.el9_60:5.14.0-570.84.1.el9_6
Red Hat:rhel_eus:9.6::appstreamkernel-64k-debug-devel-matchedbefore 0:5.14.0-570.84.1.el9_60:5.14.0-570.84.1.el9_6
Red Hat:rhel_eus:9.6::appstreamkernel-64k-debuginfobefore 0:5.14.0-570.84.1.el9_60:5.14.0-570.84.1.el9_6
Red Hat:rhel_eus:9.6::appstreamkernel-64k-develbefore 0:5.14.0-570.84.1.el9_60:5.14.0-570.84.1.el9_6
Red Hat:rhel_eus:9.6::appstreamkernel-64k-devel-matchedbefore 0:5.14.0-570.84.1.el9_60:5.14.0-570.84.1.el9_6
Red Hat:rhel_eus:9.6::appstreamkernel-debug-debuginfobefore 0:5.14.0-570.84.1.el9_60:5.14.0-570.84.1.el9_6
Red Hat:rhel_eus:9.6::appstreamkernel-debug-develbefore 0:5.14.0-570.84.1.el9_60:5.14.0-570.84.1.el9_6
Red Hat:rhel_eus:9.6::appstreamkernel-debug-devel-matchedbefore 0:5.14.0-570.84.1.el9_60:5.14.0-570.84.1.el9_6
Red Hat:rhel_eus:9.6::appstreamkernel-debuginfobefore 0:5.14.0-570.84.1.el9_60:5.14.0-570.84.1.el9_6
Red Hat:rhel_eus:9.6::appstreamkernel-debuginfo-common-aarch64before 0:5.14.0-570.84.1.el9_60:5.14.0-570.84.1.el9_6
Red Hat:rhel_eus:9.6::appstreamkernel-debuginfo-common-ppc64lebefore 0:5.14.0-570.84.1.el9_60:5.14.0-570.84.1.el9_6
Red Hat:rhel_eus:9.6::appstreamkernel-debuginfo-common-s390xbefore 0:5.14.0-570.84.1.el9_60:5.14.0-570.84.1.el9_6
Red Hat:rhel_eus:9.6::appstreamkernel-debuginfo-common-x86_64before 0:5.14.0-570.84.1.el9_60:5.14.0-570.84.1.el9_6
Red Hat:rhel_eus:9.6::appstreamkernel-develbefore 0:5.14.0-570.84.1.el9_60:5.14.0-570.84.1.el9_6
Red Hat:rhel_eus:9.6::appstreamkernel-devel-matchedbefore 0:5.14.0-570.84.1.el9_60:5.14.0-570.84.1.el9_6
Red Hat:rhel_eus:9.6::appstreamkernel-docbefore 0:5.14.0-570.84.1.el9_60:5.14.0-570.84.1.el9_6
Red Hat:rhel_eus:9.6::appstreamkernel-rt-64k-debug-debuginfobefore 0:5.14.0-570.84.1.el9_60:5.14.0-570.84.1.el9_6
Red Hat:rhel_eus:9.6::appstreamkernel-rt-64k-debuginfobefore 0:5.14.0-570.84.1.el9_60:5.14.0-570.84.1.el9_6
Red Hat:rhel_eus:9.6::appstreamkernel-rt-debug-debuginfobefore 0:5.14.0-570.84.1.el9_60:5.14.0-570.84.1.el9_6
Red Hat:rhel_eus:9.6::appstreamkernel-rt-debuginfobefore 0:5.14.0-570.84.1.el9_60:5.14.0-570.84.1.el9_6
Red Hat:rhel_eus:9.6::appstreamkernel-tools-debuginfobefore 0:5.14.0-570.84.1.el9_60:5.14.0-570.84.1.el9_6

+72

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV
    90Now
  • CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe KEV
    89Now
  • CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
    85Now

Published before and after this one in the same product

  • ← EarlierCVE-2025-21861Mar 12, 2025 · mm/migrate_device: don't add folio to be freed to LRU in migrate_device_finalize()
    22Monitor
  • ← EarlierCVE-2025-21862Mar 12, 2025 · drop_monitor: fix incorrect initialization order
    22Monitor
  • Later →CVE-2025-21864Mar 12, 2025 · tcp: drop secpath at the same time as we currently drop dst
    22Monitor

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 Linux18eae8420081ef8e043ad455937bfb470ef08607Vendor (CNA)
Linux Linux1e988c3fe1264708f4f92109203ac5b1d65de50bVendor (CNA)
Linux Linux506b9b5e8c2d2a411ea8fe361333f5081c56d23aVendor (CNA)
Linux Linux87e9eef43c758da267f6332678058a79764c7ebaVendor (CNA)
Linux Linuxb9826e3b26ec031e9063f64a7c735449c43955e4Vendor (CNA)
Linux Linuxd261ead565a080e3411b0dd04e6d58a52471cac8Vendor (CNA)
Linux Linuxfdbfd52bd8b85ed6783365ff54c82ab7067bd61bVendor (CNA)
azl3 kernel 6.6.78.1-3 on Azure Linux 3.06.6.82.1-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
azl3 kernel 6.6.82.1-1 on Azure Linux 3.06.6.82.1-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
cbl2 kernel 5.15.202.1-1 on CBL-Mariner 2.0Release NotesMicrosoft (MSRC)
debian:linux6.1.176-1 · Debian:12Package registry (OSV)
red hat:kernel-64k-debug-debuginfo0:5.14.0-570.84.1.el9_6 · Red Hat:rhel_eus:9.6::appstreamPackage registry (OSV)
red hat:kernel-64k-debug-devel0:5.14.0-570.84.1.el9_6 · Red Hat:rhel_eus:9.6::appstreamPackage registry (OSV)
red hat:kernel-64k-debug-devel-matched0:5.14.0-570.84.1.el9_6 · Red Hat:rhel_eus:9.6::appstreamPackage registry (OSV)
red hat:kernel-64k-debuginfo0:5.14.0-570.84.1.el9_6 · Red Hat:rhel_eus:9.6::appstreamPackage registry (OSV)
red hat:kernel-64k-devel0:5.14.0-570.84.1.el9_6 · Red Hat:rhel_eus:9.6::appstreamPackage registry (OSV)
red hat:kernel-64k-devel-matched0:5.14.0-570.84.1.el9_6 · Red Hat:rhel_eus:9.6::appstreamPackage registry (OSV)
red hat:kernel-debug-debuginfo0:5.14.0-570.84.1.el9_6 · Red Hat:rhel_eus:9.6::appstreamPackage registry (OSV)
red hat:kernel-debug-devel0:5.14.0-570.84.1.el9_6 · Red Hat:rhel_eus:9.6::appstreamPackage registry (OSV)
red hat:kernel-debug-devel-matched0:5.14.0-570.84.1.el9_6 · Red Hat:rhel_eus:9.6::appstreamPackage registry (OSV)
red hat:kernel-debuginfo0:5.14.0-570.84.1.el9_6 · Red Hat:rhel_eus:9.6::appstreamPackage registry (OSV)
red hat:kernel-debuginfo-common-aarch640:5.14.0-570.84.1.el9_6 · Red Hat:rhel_eus:9.6::appstreamPackage registry (OSV)
red hat:kernel-debuginfo-common-ppc64le0:5.14.0-570.84.1.el9_6 · Red Hat:rhel_eus:9.6::appstreamPackage registry (OSV)
suse:kernel-livepatch-MICRO-6-0-RT_Update_71-1.3 · SUSE:Linux Micro 6.0Package registry (OSV)
suse:kernel-rt6.4.0-30.1 · SUSE:Linux Micro 6.0Package registry (OSV)
suse:kernel-source-rt6.4.0-30.1 · SUSE:Linux Micro 6.0Package 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-primary

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 (9 more)

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

All records