BlackTreeIndependent security intelligence
← Back to the CVE catalogue
Full vulnerability report · 2026
CVE-2026-64458High confidence

mm/damon/ops-common: handle extreme intervals in damon_hot_score()

Linux · Linux

UnscoredAssess manually
Recommended action
Needs assessment

No CVSS base score is available from the CNA, CISA ADP or NIST. Absence of a score is not evidence of low risk; review the vendor advisory, affected exposure and exploit evidence.

Patch available
Distribution package intelligence

Ubuntu vendor package status

Canonical’s release and source-package findings are shown separately from local repository availability.

20 package states
Repository candidate not checked

A published vendor fix does not prove that a matching update is enabled and installable on a particular asset. Confirm the local package candidate before scheduling remediation.

Ubuntu releaseSource packageVendor stateFixed versionEvidence
Ubuntu 24.04 LTSnoble · standard archivelinuxAffected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical record ↗Source updated 8 Sept 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-awsAffected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical record ↗Source updated 8 Sept 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-azureAffected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical record ↗Source updated 8 Sept 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-azure-fdeAffected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical record ↗Source updated 8 Sept 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-azure-nvidiaAffected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical record ↗Source updated 8 Sept 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-gcpAffected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical record ↗Source updated 8 Sept 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-gkeAffected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical record ↗Source updated 8 Sept 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-gkeopAffected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical record ↗Source updated 8 Sept 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-ibmAffected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical record ↗Source updated 8 Sept 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-lowlatencyAffected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical record ↗Source updated 8 Sept 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-nvidiaAffected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical record ↗Source updated 8 Sept 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-nvidia-lowlatencyAffected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical record ↗Source updated 8 Sept 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-nvidia-tegraAffected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical record ↗Source updated 8 Sept 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-oem-6.11Affected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical record ↗Source updated 8 Sept 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-oracleAffected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical record ↗Source updated 8 Sept 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-raspiAffected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical record ↗Source updated 8 Sept 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-raspi-realtimeAffected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical record ↗Source updated 8 Sept 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-realtimeAffected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical record ↗Source updated 8 Sept 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-riscvAffected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical record ↗Source updated 8 Sept 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-xilinxAffected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical record ↗Source updated 8 Sept 2026
Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Select the national-authority views to include. The exact source language is shown on each matched advisory. Your choice is remembered on this device and encoded in the shareable URL.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2026-48802

No EUVD known-exploited evidence

ENISA has published the identifier mapping but no EUVD description has been stored yet.

EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
Not supplied in the stored EUVD record
Advisory evidence
No linked advisory details stored yet
Recommended actionNeeds assessment

No CVSS base score is available from the CNA, CISA ADP or NIST. Absence of a score is not evidence of low risk; review the vendor advisory, affected exposure and exploit evidence.

Patch available
01

What, why and how

In the Linux kernel, the following vulnerability has been resolved: mm/damon/ops-common: handle extreme intervals in damon_hot_score() Fix three issues in damon_hot_score() that comes from wrong handling of extreme (zero or too high) monitoring intervals user setup. When the user sets sampling interval zero, damon_max_nr_accesses(), which is called from damon_hot_score(), causes a divide-by-zero. Needless to say, it is a problem. When the user sets the aggregation interval zero, the function returns zero. It is wrong, since the real maximum nr_acceses in the setup should be one. Worse yet, it can cause another divide-by-zero from its caller, damon_hot_score(), since it uses damon_max_nr_accesses() return value as a denominator. When the user sets the aggregation interval very high, damon_hot_score() could return a value out of [0, DAMOS_MAX_SCORE] range. Since the return value is used as an index to the regions_score_histogram array, which is DAMOS_MAX_SCORE+1 size, it causes out of bounds array access. The issues can be relatively easily reproduced like below. The sysfs write permission is required, though. # ./damo start --damos_action lru_prio --damos_quota_space 100M \ --damos_quota_interval 1s # cd /sys/kernel/mm/damon/admin/kdamonds/0 # echo 0 > contexts/0/monitoring_attrs/intervals/sample_us # echo 0 > contexts/0/monitoring_attrs/intervals/aggr_us # echo commit > state # dmesg [...] [ 131.329762] Oops: divide error: 0000 [#1] SMP NOPTI [...] [ 131.336089] RIP: 0010:damon_hot_score+0x27/0xd0 [...] Fix the divide-by-zero intervals problems by explicitly handling the zero intervals in damon_max_nr_accesses(). Fix the out-of-bound array access by applying [0, DAMOS_MAX_SCORE] bounds before returning from damon_hot_score(). The issue was discovered [1] by Sashiko.

What

In the Linux kernel, the following vulnerability has been resolved: mm/damon/ops-common: handle extreme intervals in damon_hot_score() Fix three issues in damon_hot_score() that comes from wrong handling of extreme (zero or too high) monitoring intervals user setup. When the user sets sampling interval zero, damon_max_nr_accesses(), which is called from damon_hot_score(), causes a divide-by-zero. Needless to say, it is a problem. When the user sets the aggregation interval zero, the function returns zero. It is wrong, since the real maximum nr_acceses in the setup should be one. Worse yet, it can cause another divide-by-zero from its caller, damon_hot_score(), since it uses damon_max_nr_accesses() return value as a denominator. When the user sets the aggregation interval very high, damon_hot_score() could return a value out of [0, DAMOS_MAX_SCORE] range. Since the return value is used as an index to the regions_score_histogram array, which is DAMOS_MAX_SCORE+1 size, it causes out of bounds array access. The issues can be relatively easily reproduced like below. The sysfs write permission is required, though. # ./damo start --damos_action lru_prio --damos_quota_space 100M \ --damos_quota_interval 1s # cd /sys/kernel/mm/damon/admin/kdamonds/0 # echo 0 > contexts/0/monitoring_attrs/intervals/sample_us # echo 0 > contexts/0/monitoring_attrs/intervals/aggr_us # echo commit > state # dmesg [...] [ 131.329762] Oops: divide error: 0000 [#1] SMP NOPTI [...] [ 131.336089] RIP: 0010:damon_hot_score+0x27/0xd0 [...] Fix the divide-by-zero intervals problems by explicitly handling the zero intervals in damon_max_nr_accesses(). Fix the out-of-bound array access by applying [0, DAMOS_MAX_SCORE] bounds before returning from damon_hot_score(). The issue was discovered [1] by Sashiko.

Why

The current structured CVE record identifies a security weakness, but the root cause requires confirmation in the linked vendor material.

How

An attacker operating through the affected interface may attempt exploitation when the stated preconditions are met. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

What

In the Linux kernel, the following vulnerability has been resolved: mm/damon/ops-common: handle extreme intervals in damon_hot_score() Fix three issues in damon_hot_score() that comes from wrong handling of extreme (zero or too high) monitoring intervals user setup. When the user sets sampling interval zero, damon_max_nr_accesses(), which is called from damon_hot_score(), causes a divide-by-zero. Needless to say, it is a problem. When the user sets the aggregation interval zero, the function returns zero. It is wrong, since the real maximum nr_acceses in the setup should be one. Worse yet, it can cause another divide-by-zero from its caller, damon_hot_score(), since it uses damon_max_nr_accesses() return value as a denominator. When the user sets the aggregation interval very high, damon_hot_score() could return a value out of [0, DAMOS_MAX_SCORE] range. Since the return value is used as an index to the regions_score_histogram array, which is DAMOS_MAX_SCORE+1 size, it causes out of bounds array access. The issues can be relatively easily reproduced like below. The sysfs write permission is required, though. # ./damo start --damos_action lru_prio --damos_quota_space 100M \ --damos_quota_interval 1s # cd /sys/kernel/mm/damon/admin/kdamonds/0 # echo 0 > contexts/0/monitoring_attrs/intervals/sample_us # echo 0 > contexts/0/monitoring_attrs/intervals/aggr_us # echo commit > state # dmesg [...] [ 131.329762] Oops: divide error: 0000 [#1] SMP NOPTI [...] [ 131.336089] RIP: 0010:damon_hot_score+0x27/0xd0 [...] Fix the divide-by-zero intervals problems by explicitly handling the zero intervals in damon_max_nr_accesses(). Fix the out-of-bound array access by applying [0, DAMOS_MAX_SCORE] bounds before returning from damon_hot_score(). The issue was discovered [1] by Sashiko.

Why

The current structured CVE record identifies a security weakness, but the root cause requires confirmation in the linked vendor material.

How

An attacker operating through the affected interface may attempt exploitation when the stated preconditions are met. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
None recorded

No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.

Likely attack path
the affected interface → vulnerable operation → cause the confidentiality, integrity or availability impact described by the vendor
Attack surface
Unspecified
Privileges required
Not stated in the selected CVSS metric
User interaction
Not stated in the selected CVSS metric
Attack complexity
Not stated in the selected CVSS metric
Security boundary
Not stated in the selected CVSS metric
Weakness
?CWE means Common Weakness Enumeration.
CWE not yet assigned
CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
Not available from the selected scoring authority.
Post-exploitation / living off the land
No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

BSI · German · WID-SEC-W-2026-2527Linux Kernel: Mehrere Schwachstellen

Ein Angreifer kann mehrere Schwachstellen im Linux Kernel ausnutzen, um nicht näher spezifizierte Angriffe durchzuführen, dazu können DoS-Angriffe, die Offenlegung von Informationen, die Beschädigung des Speichers oder die Umgehung von Sicherheitsmaßnahmen gehören.

Official advisory
CERT-FR · French · CERTFR-2026-AVI-1031Multiples vulnérabilités dans le noyau Linux de Debian LTS

d?id=CVE-2026-64446 Référence CVE CVE-2026-64448 https://www.cve.org/CVERecord?id=CVE-2026-64448 Référence CVE CVE-2026-64449 https://www.cve.org/CVERecord?id=CVE-2026-64449 Référence CVE CVE-2026-64450 https://www.cve.org/CVERecord?id=CVE-2026-64450 Référence CVE CVE-2026-64452 https://www.cve.org/CVERecord?id=CVE-2026-64452 Référence CVE CVE-2026-64454 https://www.cve.org/CVERecord?id=CVE-2026-64454 Référence CVE CVE-2026-64455 https://www.cve.org/CVERecord?id=CVE-2026-64455 Référence CVE CVE-2026-64456 https://www.cve.org/CVERecord?id=CVE-2026-64456 Référence CVE CVE-2026-64457 https://www.cve.org/CVERecord?id=CVE-2026-64457 Référence CVE CVE-2026-64458 https://www.cve.org/CVERecord?id=CVE-2026-64458 Référence CVE CVE-2026-64461 https://www.cve.org/CVERecord?id=CVE-2026-64461 Référence CVE CVE-2026-64462 https://www.cve.org/CVERecord?id=CVE-2026-64462 Référence CVE CVE-2026-64463 https://www.cve.org/CVERecord?id=CVE-2026-64463 Référence CVE CVE-2026-64465 https://www.cve.org/CVERecord?id=CVE-2026-64465 Référence CVE CVE-2026-64468 https://www.cve.org/CVERecord?id=CVE-2026-64468 Référence CVE CVE-2026-64469 https://www.cve.org/CVERecord?id=CVE-2026-64469 Référence CVE CVE-2026-64470 https://www.cve.org/CVERecord?id=CVE-2026-64470 Référence CVE CVE-2026-64471 https://www.cve.org/CVERecord?id=

Official advisory
CERT-FR · French · CERTFR-2026-AVI-0982Multiples vulnérabilités dans le noyau Linux de Debian LTS

d?id=CVE-2026-64445 Référence CVE CVE-2026-64446 https://www.cve.org/CVERecord?id=CVE-2026-64446 Référence CVE CVE-2026-64448 https://www.cve.org/CVERecord?id=CVE-2026-64448 Référence CVE CVE-2026-64449 https://www.cve.org/CVERecord?id=CVE-2026-64449 Référence CVE CVE-2026-64450 https://www.cve.org/CVERecord?id=CVE-2026-64450 Référence CVE CVE-2026-64452 https://www.cve.org/CVERecord?id=CVE-2026-64452 Référence CVE CVE-2026-64454 https://www.cve.org/CVERecord?id=CVE-2026-64454 Référence CVE CVE-2026-64455 https://www.cve.org/CVERecord?id=CVE-2026-64455 Référence CVE CVE-2026-64456 https://www.cve.org/CVERecord?id=CVE-2026-64456 Référence CVE CVE-2026-64458 https://www.cve.org/CVERecord?id=CVE-2026-64458 Référence CVE CVE-2026-64461 https://www.cve.org/CVERecord?id=CVE-2026-64461 Référence CVE CVE-2026-64462 https://www.cve.org/CVERecord?id=CVE-2026-64462 Référence CVE CVE-2026-64465 https://www.cve.org/CVERecord?id=CVE-2026-64465 Référence CVE CVE-2026-64468 https://www.cve.org/CVERecord?id=CVE-2026-64468 Référence CVE CVE-2026-64469 https://www.cve.org/CVERecord?id=CVE-2026-64469 Référence CVE CVE-2026-64470 https://www.cve.org/CVERecord?id=CVE-2026-64470 Référence CVE CVE-2026-64471 https://www.cve.org/CVERecord?id=CVE-2026-64471 Référence CVE CVE-2026-64472 https://www.cve.org/CVERecord?id=

Official advisory
03

Patch and workaround

Operational remediation based on structured source evidence.

Status
?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Patch available
Affected
198f0f4c58b9f481e4e51c8c70a6ab9852bbab7f < 58321b4e6e4f0f412069ab27ccdd56292757343a; 198f0f4c58b9f481e4e51c8c70a6ab9852bbab7f < 74fef68d521150281e36cdaa20e9e1ee3e3aa146; 198f0f4c58b9f481e4e51c8c70a6ab9852bbab7f < ef2ae10a4582bc92b7e944181bbd2f87f3d30f3a; 198f0f4c58b9f481e4e51c8c70a6ab9852bbab7f < 9c8f31eaae6140ecadec0c07320498a944556de2; 198f0f4c58b9f481e4e51c8c70a6ab9852bbab7f < 76e415ea88d20f022ed5cfcf78c50e156a267e91; 198f0f4c58b9f481e4e51c8c70a6ab9852bbab7f < 35d4a3cf70a855b50e53189ac2f8463e20a02046; 5.16
Fixed
< 5.16; 6.1.178 ≤ 6.1.*; 6.6.145 ≤ 6.6.*; 6.12.96 ≤ 6.12.*; 6.18.39 ≤ 6.18.*; 7.1.4 ≤ 7.1.*; 7.2 ≤ *
Action
Review the linked authoritative reference and apply the recorded fixed release appropriate to the affected product branch.
Workaround
No verified workaround is recorded. Limit untrusted access and use least privilege until authoritative guidance is available.
04

Evidence and provenance

Published 25 Jul 2026 · Last source change 17 Aug 2026, 04:56 UTC · CWE not yet assigned

CVE recordCVE.org · 5.2
CVSS sourceUnavailable
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-08-14
European sourceENISA EUVD · EUVD-2026-48802
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceUnavailable
NVD statusNVD received

Missing structured fields: CVSS base score, CWE classification. Missing data is not evidence of low risk; review the primary advisory.

Material change intelligence

What changed after publication

View recent updates →
  1. Affected versionsThe structured affected or fixed version information changed.
    Before
    198f0f4c58b9f481e4e51c8c70a6ab9852bbab7f < 58321b4e6e4f0f412069ab27ccdd56292757343a; 198f0f4c58b9f481e4e51c8c70a6ab9852bbab7f < 74fef68d521150281e36cdaa20e9e1ee3e3aa146; 198f0f4c58b9f481e4e51c8c70a6ab9852bbab7f < ef2ae10a4582bc92b7e944181bbd2f87f3d30f3a; 198f0f4c58b9f481e4e51c8c70a6ab9852bbab7f < 9c8f31eaae6140ecadec0c07320498a944556de2; 198f0f4c58b9f481e4e51c8c70a6ab9852bbab7f < 76e415ea88d20f022ed5cfcf78c50e156a267e91; 198f0f4c58b9f481e4e51c8c70a6ab9852bbab7f < 35d4a3cf70a855b50e53189ac2f8463e20a02046; 5.16 · Fixed: < 5.16; 6.1.178 ≤ 6.1.*; 6.6.145 ≤ 6.6.*; 6.12.96 ≤ 6.12.*; 6.18.39 ≤ 6.18.*; 7.1.4 ≤ 7.1.*; 7.2-rc3 ≤ *
    After
    198f0f4c58b9f481e4e51c8c70a6ab9852bbab7f < 58321b4e6e4f0f412069ab27ccdd56292757343a; 198f0f4c58b9f481e4e51c8c70a6ab9852bbab7f < 74fef68d521150281e36cdaa20e9e1ee3e3aa146; 198f0f4c58b9f481e4e51c8c70a6ab9852bbab7f < ef2ae10a4582bc92b7e944181bbd2f87f3d30f3a; 198f0f4c58b9f481e4e51c8c70a6ab9852bbab7f < 9c8f31eaae6140ecadec0c07320498a944556de2; 198f0f4c58b9f481e4e51c8c70a6ab9852bbab7f < 76e415ea88d20f022ed5cfcf78c50e156a267e91; 198f0f4c58b9f481e4e51c8c70a6ab9852bbab7f < 35d4a3cf70a855b50e53189ac2f8463e20a02046; 5.16 · Fixed: < 5.16; 6.1.178 ≤ 6.1.*; 6.6.145 ≤ 6.6.*; 6.12.96 ≤ 6.12.*; 6.18.39 ≤ 6.18.*; 7.1.4 ≤ 7.1.*; 7.2 ≤ *
    CNA
Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
Free version - for non-commercial use only.CVE-2026-64458 · cve.blacktree.nl