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NVD / CVE Program· CNA Linux

CVE-2025-40124: sparc: fix accurate exception reporting in copy_{from_to}_user for UltraSPARC III

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: 0.16% (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 1198077606aeffb102587c6ea079ce99641c99d4, 1857cdca12c4aff58bf26a7005a4d02850c29927, 4.5.

Low priority for now. Upgrade to Linux Linux 1198077606aeffb102587c6ea079ce99641c99d4, 1857cdca12c4aff58bf26a7005a4d02850c29927, 4.5 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: sparc: fix accurate exception reporting in copy_{from_to}_user for UltraSPARC III Anthony Yznaga tracked down that a BUG_ON in ext4 code with large folios enabled resulted from copy_from_user() returning impossibly large values greater than the size to be copied. This lead to __copy_from_iter() returning impossible values instead of the actual number of bytes it was able to copy. The BUG_ON has been reported in https://lore.kernel.org/r/b14f55642207e63e907965e209f6323a0df6dcee.camel@physik.fu-berlin.de The referenced commit introduced exception handlers on user-space memory references in copy_from_user and copy_to_user. These handlers return from the respective function and calculate the remaining bytes left to copy using the current register contents. The exception handlers expect that %o2 has already been masked during the bulk copy loop, but the masking was performed after that loop. This will fix the return value of copy_from_user and copy_to_user in the faulting case. The behaviour of memcpy stays unchanged.

HighCVSS 7.8 · v3.1—No exploit Fix available
Published
Nov 12, 2025
Updated
Oct 19, 2026
EPSS
0.1% · 5th 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

    • 1c7e17b1c4d60cc5aa575460f7efb73686dd3b39, ac663c54f40b2830b1ca32d1ae9d683fe248b14c, 4.9affected
    • ee841d0aff649164080e445e84885015958d8ff4 and later · before fdd43fe6d286f27b826572457a89c926f97e2d3aaffected · git
    • ee841d0aff649164080e445e84885015958d8ff4 and later · before 1198077606aeffb102587c6ea079ce99641c99d4affected · git
    • ee841d0aff649164080e445e84885015958d8ff4 and later · before 1857cdca12c4aff58bf26a7005a4d02850c29927affected · git
    • ee841d0aff649164080e445e84885015958d8ff4 and later · before 91eda032eb16e5d2be27c95584665bc555bb5a90affected · git
    • ee841d0aff649164080e445e84885015958d8ff4 and later · before dc766c4830a7e1e1ee9d7f77d4ab344f2eb23c8eaffected · git
    • ee841d0aff649164080e445e84885015958d8ff4 and later · before 5ef9c94d7110e90260c06868cf1dcf899b9f25eeaffected · git
    • ee841d0aff649164080e445e84885015958d8ff4 and later · before e50377c6b3f278c9f3ef017ffce17f5fcc9dace4affected · git
    • ee841d0aff649164080e445e84885015958d8ff4 and later · before 47b49c06eb62504075f0f2e2227aee2e2c2a58b3affected · git
    • 4.4.34 and later · before 4.5affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.158-16.1.158-1
Debian:13linuxbefore 6.12.57-16.12.57-1
Debian:14linuxbefore 6.17.6-16.17.6-1

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-2025-40122Nov 12, 2025 · perf/x86/intel: Fix IA32_PMC_x_CFG_B MSRs access error
    0Monitor
  • ← EarlierCVE-2025-40123Nov 12, 2025 · bpf: Enforce expected_attach_type for tailcall compatibility
    31Monitor
  • Later →CVE-2025-40125Nov 12, 2025 · blk-mq: check kobject state_in_sysfs before deleting in blk_mq_unregister_hctx
    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 Linux1198077606aeffb102587c6ea079ce99641c99d4Vendor (CNA)
Linux Linux1857cdca12c4aff58bf26a7005a4d02850c29927Vendor (CNA)
Linux Linux4.5Vendor (CNA)
Linux Linux4.9Vendor (CNA)
Linux Linux47b49c06eb62504075f0f2e2227aee2e2c2a58b3Vendor (CNA)
Linux Linux5ef9c94d7110e90260c06868cf1dcf899b9f25eeVendor (CNA)
Linux Linux91eda032eb16e5d2be27c95584665bc555bb5a90Vendor (CNA)
Linux Linuxdc766c4830a7e1e1ee9d7f77d4ab344f2eb23c8eVendor (CNA)
Linux Linuxe50377c6b3f278c9f3ef017ffce17f5fcc9dace4Vendor (CNA)
Linux Linuxfdd43fe6d286f27b826572457a89c926f97e2d3aVendor (CNA)
debian:linux6.1.158-1 · 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. Fix✗ → ✓

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

References

Show all references (7 more)

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

All records