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NVD / CVE Program· CNA Linux

CVE-2025-39909: mm/damon/lru_sort: avoid divide-by-zero in damon_lru_sort_apply_parameters()

Noroxi assessment

Priority: Monitor (action score 22/100)

  • 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 326a4b3750c71af3f3c52399ec4dbe33b6da4c26, 711f19dfd783ffb37ca4324388b9c4cb87e71363, 74e391f7da7d9d5235a3cca88ee9fc18f720c75b; azl3 kernel 6.6.104.2-4 on Azure Linux 3.0 6.6.112.1-1.

Low priority for now. Upgrade to Linux Linux 326a4b3750c71af3f3c52399ec4dbe33b6da4c26, 711f19dfd783ffb37ca4324388b9c4cb87e71363, 74e391f7da7d9d5235a3cca88ee9fc18f720c75b; azl3 kernel 6.6.104.2-4 on Azure Linux 3.0 6.6.112.1-1 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: mm/damon/lru_sort: avoid divide-by-zero in damon_lru_sort_apply_parameters() Patch series "mm/damon: avoid divide-by-zero in DAMON module's parameters application". DAMON's RECLAIM and LRU_SORT modules perform no validation on user-configured parameters during application, which may lead to division-by-zero errors. Avoid the divide-by-zero by adding validation checks when DAMON modules attempt to apply the parameters. This patch (of 2): During the calculation of 'hot_thres' and 'cold_thres', either 'sample_interval' or 'aggr_interval' is used as the divisor, which may lead to division-by-zero errors. Fix it by directly returning -EINVAL when such a case occurs. Additionally, since 'aggr_interval' is already required to be set no smaller than 'sample_interval' in damon_set_attrs(), only the case where 'sample_interval' is zero needs to be checked.

MediumCVSS 5.5 · v3.1—No exploit Fix available
Published
Oct 1, 2025
Updated
Oct 19, 2026
EPSS
0.1% · 4th percentile

Report tools

JSON

Action score

22

Monitor

Low priority for now.

CVSS
22 / 40 · 5.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

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  • 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 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?

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
debiandebian linux

Affected versions

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

  • debian debian linux11.0
  • linux linux kernel6.0 and later · before 6.1.153
  • linux linux kernel6.2 and later · before 6.6.107
  • linux linux kernel6.7 and later · before 6.12.48
  • linux linux kernel6.13 and later · before 6.16.8
  • linux linux kernel6.17

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

    • 6.0affected
    • 40e983cca9274e177bd5b9379299b44d9536ac68 and later · before 74e391f7da7d9d5235a3cca88ee9fc18f720c75baffected · git
    • 40e983cca9274e177bd5b9379299b44d9536ac68 and later · before 7bb675c9f0257840d33e5d1337d7e3afdd74a6bfaffected · git
    • 40e983cca9274e177bd5b9379299b44d9536ac68 and later · before af0ae62b935317bed1a1361c8c9579db9d300e70affected · git
    • 40e983cca9274e177bd5b9379299b44d9536ac68 and later · before 326a4b3750c71af3f3c52399ec4dbe33b6da4c26affected · git
    • 40e983cca9274e177bd5b9379299b44d9536ac68 and later · before 711f19dfd783ffb37ca4324388b9c4cb87e71363affected · git
    • before 6.0not affected · semver
    • 6.1.153 and later · up to and including 6.1.*not affected · semver
    • 6.6.107 and later · up to and including 6.6.*not affected · semver
    • 6.12.48 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 6.1.153-16.1.153-1
Debian:13linuxbefore 6.12.48-16.12.48-1
Debian:14linuxbefore 6.16.8-16.16.8-1

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-2025-39908Oct 1, 2025 · net: dev_ioctl: take ops lock in hwtstamp lower paths
    22Monitor
  • ← EarlierCVE-2022-50424Oct 1, 2025 · wifi: mt76: mt7921: resource leaks at mt7921_check_offload_capability()
    22Monitor
  • Later →CVE-2022-50425Oct 1, 2025 · x86/fpu: Fix copy_xstate_to_uabi() to copy init states correctly
    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 Linux326a4b3750c71af3f3c52399ec4dbe33b6da4c26Vendor (CNA)
Linux Linux711f19dfd783ffb37ca4324388b9c4cb87e71363Vendor (CNA)
Linux Linux74e391f7da7d9d5235a3cca88ee9fc18f720c75bVendor (CNA)
Linux Linux7bb675c9f0257840d33e5d1337d7e3afdd74a6bfVendor (CNA)
Linux Linuxaf0ae62b935317bed1a1361c8c9579db9d300e70Vendor (CNA)
azl3 kernel 6.6.104.2-4 on Azure Linux 3.06.6.112.1-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
debian:linux6.1.153-1 · 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.

  • CVE-2024-26945518 days apartcrypto: iaa - Fix nr_cpus < nr_iaa case
    33Monitor
  • CVE-2025-399160 days apartmm/damon/reclaim: avoid divide-by-zero in damon_reclaim_apply_parameters()
    22Monitor
  • CVE-2025-399548 days apartclk: sunxi-ng: mp: Fix dual-divider clock rate readback
    22Monitor
  • CVE-2025-3974220 days apartRDMA: hfi1: fix possible divide-by-zero in find_hw_thread_mask()
    22Monitor
  • CVE-2025-3871927 days apartnet: hibmcge: fix the division by zero issue
    22Monitor
  • CVE-2025-3851946 days apartmm/damon: fix divide by zero in damon_get_intervals_score()
    22Monitor

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

Weakness class (CWE)

CWE-369 · Divide By Zero

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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 (5 more)

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

All records