7.8

CVE-2025-40124: linux

CVSS: 7.8v3.1HighDeferred
AliasesUBUNTU-CVE-2025-40124DEBIAN-CVE-2025-40124
Published 12-11-2025Last modified 05-08-2026
Open JSON

Vulnerability summary

CVE-2025-40124 is a high (CVSS 7.8) vulnerability in linux. EPSS estimates a 0.17% chance of exploitation in the next 30 days, higher than 5.4% of scored vulnerabilities.

Overall risk
31/100
0100
Medium · default modelHow is this calculated?
CVSS score
7.8/10
010
High · v3.1 (CVE.org)
EPSS score
0.17%
0%100%
Low · +0.01 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 30 · Related 29
DLA-4379-1USN-8029-1USN-8029-2USN-8029-3USN-8030-1USN-8033-1

Timeline

  1. 12-11-2025
    PublishedVulnerability first disclosed.
  2. 05-08-2026
    Last modifiedVulnerability information updated.

Description

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.

CVSS metrics

4 scores · 4 sources · 1 version

EPSS trend

Probability

0.17%

Chance of exploitation in the next 30 days

Percentile

5%

Versus all other CVEs

30-day change

+0.01 pp

From 0.15% on 19-09-2026

19-09-202619-10-2026
EPSS score
0.17%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

No weakness data has been published for this record.

Affected systems

Ubuntu153 products
  • linuxAll versions (No fix recorded) | < 5.15.0-170.180 | < 6.8.0-106.106 | < 6.17.0-14.14
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-awsAll versions (No fix recorded) | < 5.15.0-1100.107 | < 6.8.0-1050.53 | < 6.17.0-1007.7
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Debian1 product
  • linux< 6.1.158-1 | < 6.12.57-1 | < 6.17.6-1
Linux1 product
  • linux≥ ee841d0aff649164080e445e84885015958d8ff4, < fdd43fe6d286f27b826572457a89c926f97e2d3a | ≥ ee841d0aff649164080e445e84885015958d8ff4, < 1198077606aeffb102587c6ea079ce99641c99d4 | ≥ ee841d0aff649164080e445e84885015958d8ff4, < 1857cdca12c4aff58bf26a7005a4d02850c29927 | ≥ ee841d0aff649164080e445e84885015958d8ff4, < 91eda032eb16e5d2be27c95584665bc555bb5a90 | ≥ ee841d0aff649164080e445e84885015958d8ff4, < dc766c4830a7e1e1ee9d7f77d4ab344f2eb23c8e | ≥ ee841d0aff649164080e445e84885015958d8ff4, < 5ef9c94d7110e90260c06868cf1dcf899b9f25ee | ≥ ee841d0aff649164080e445e84885015958d8ff4, < e50377c6b3f278c9f3ef017ffce17f5fcc9dace4 | ≥ ee841d0aff649164080e445e84885015958d8ff4, < 47b49c06eb62504075f0f2e2227aee2e2c2a58b3 | 1c7e17b1c4d60cc5aa575460f7efb73686dd3b39 | ac663c54f40b2830b1ca32d1ae9d683fe248b14c | ≥ 4.4.34, < 4.5 | ≥ 4.8.10, < 4.9 | 4.9

3 vendors · 155 products

References

41 links
Show all 41 references