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Full vulnerability report · 2025
CVE-2025-21691High confidence

cachestat: fix page cache statistics permission checking

Linux · Linux

5.5MediumCVSS 3.1
Recommended action
Scheduled

Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.

Patch available
Distribution package intelligence

Ubuntu vendor package status

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

19 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 11 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 11 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 11 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 11 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 11 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 11 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 11 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 11 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 11 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 11 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 11 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 11 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 11 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 11 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 11 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 11 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 11 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 11 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 11 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-2025-2640

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 actionScheduled

Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.

Patch available
01

What, why and how

In the Linux kernel, the following vulnerability has been resolved: cachestat: fix page cache statistics permission checking When the 'cachestat()' system call was added in commit cf264e1329fb ("cachestat: implement cachestat syscall"), it was meant to be a much more convenient (and performant) version of mincore() that didn't need mapping things into the user virtual address space in order to work. But it ended up missing the "check for writability or ownership" fix for mincore(), done in commit 134fca9063ad ("mm/mincore.c: make mincore() more conservative"). This just adds equivalent logic to 'cachestat()', modified for the file context (rather than vma).

What

In the Linux kernel, the following vulnerability has been resolved: cachestat: fix page cache statistics permission checking When the 'cachestat()' system call was added in commit cf264e1329fb ("cachestat: implement cachestat syscall"), it was meant to be a much more convenient (and performant) version of mincore() that didn't need mapping things into the user virtual address space in order to work. But it ended up missing the "check for writability or ownership" fix for mincore(), done in commit 134fca9063ad ("mm/mincore.c: make mincore() more conservative"). This just adds equivalent logic to 'cachestat()', modified for the file context (rather than vma).

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 local access may attempt exploitation with low privileges. 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: cachestat: fix page cache statistics permission checking When the 'cachestat()' system call was added in commit cf264e1329fb ("cachestat: implement cachestat syscall"), it was meant to be a much more convenient (and performant) version of mincore() that didn't need mapping things into the user virtual address space in order to work. But it ended up missing the "check for writability or ownership" fix for mincore(), done in commit 134fca9063ad ("mm/mincore.c: make mincore() more conservative"). This just adds equivalent logic to 'cachestat()', modified for the file context (rather than vma).

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 local access may attempt exploitation with low privileges. 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
local access → vulnerable operation → cause the confidentiality, integrity or availability impact described by the vendor
Attack surface
Local
Privileges required
Low: a basic authenticated account is required
User interaction
None
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Unchanged: impact remains within the vulnerable component's security authority
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.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Common Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.

AVLocalAttack vector: The attacker needs local access to the vulnerable system.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRLowPrivileges required: The attacker needs basic user-level privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CNoneConfidentiality impact: No direct loss is represented by this metric.INoneIntegrity impact: No direct loss is represented by this metric.AHighAvailability impact: A successful attack can cause a major loss.
Post-exploitation / living off the land
The issue can support a local privilege or sandbox boundary transition; normal system utilities may then be available in the gained context.
A

Official authority intelligence

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

BSI · German · WID-SEC-2026-2253IBM Security Verify Access: Mehrere Schwachstellen

Ein Angreifer kann mehrere Schwachstellen in IBM Security Verify Access ausnutzen, um erweiterte Berechtigungen zu erlangen, beliebigen Code auszuführen, Sicherheitsmaßnahmen zu umgehen, Daten zu manipulieren, sensible Informationen offenzulegen und andere, nicht näher bezeichnete Angriffe durchzuführen.

Official advisory ↗
BSI · German · WID-SEC-2025-0309Linux Kernel: Mehrere Schwachstellen

Ein lokaler Angreifer kann mehrere Schwachstellen in Linux Kernel ausnutzen, um einen Denial of Service Angriff durchzuführen und um seine Privilegien zu eskalieren.

Official advisory ↗
Cyber Security Agency of Singapore · English · CSA-SB-20250213Security Bulletin 13 February 2025

The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 13 February 2025, published on 13 February 2025. Open the linked bulletin for the product, severity and reference information published in that issue.

Official advisory ↗
CERT-FR · French · CERTFR-2026-AVI-0863Multiples vulnérabilités dans le noyau Linux de Red Hat

sécurité Red Hat RHSA-2026:34098 du 09 juillet 2026 https://access.redhat.com/errata/RHSA-2026:34098 Bulletin de sécurité Red Hat RHSA-2026:36956 du 09 juillet 2026 https://access.redhat.com/errata/RHSA-2026:36956 Bulletin de sécurité Red Hat RHSA-2026:36957 du 09 juillet 2026 https://access.redhat.com/errata/RHSA-2026:36957 Référence CVE CVE-2024-27398 https://www.cve.org/CVERecord?id=CVE-2024-27398 Référence CVE CVE-2024-50125 https://www.cve.org/CVERecord?id=CVE-2024-50125 Référence CVE CVE-2025-10263 https://www.cve.org/CVERecord?id=CVE-2025-10263 Référence CVE CVE-2025-21648 https://www.cve.org/CVERecord?id=CVE-2025-21648 Référence CVE CVE-2025-21691 https://www.cve.org/CVERecord?id=CVE-2025-21691 Référence CVE CVE-2025-68183 https://www.cve.org/CVERecord?id=CVE-2025-68183 Référence CVE CVE-2025-71066 https://www.cve.org/CVERecord?id=CVE-2025-71066 Référence CVE CVE-2025-71116 https://www.cve.org/CVERecord?id=CVE-2025-71116 Référence CVE CVE-2026-22984 https://www.cve.org/CVERecord?id=CVE-2026-22984 Référence CVE CVE-2026-22990 https://www.cve.org/CVERecord?id=CVE-2026-22990 Référence CVE CVE-2026-23191 https://www.cve.org/CVERecord?id=CVE-2026-23191 Référence CVE CVE-2026-23216 https://www.cve.org/CVERecord?id=CVE-2026-23216 Référence CVE CVE-2026-23270 https://www.cve.org/CVERecord?id=

Official advisory ↗
CERT-FR · French · CERTFR-2025-AVI-1057Multiples vulnérabilités dans les produits VMware

d?id=CVE-2025-21647 Référence CVE CVE-2025-21649 https://www.cve.org/CVERecord?id=CVE-2025-21649 Référence CVE CVE-2025-21659 https://www.cve.org/CVERecord?id=CVE-2025-21659 Référence CVE CVE-2025-21663 https://www.cve.org/CVERecord?id=CVE-2025-21663 Référence CVE CVE-2025-21668 https://www.cve.org/CVERecord?id=CVE-2025-21668 Référence CVE CVE-2025-21670 https://www.cve.org/CVERecord?id=CVE-2025-21670 Référence CVE CVE-2025-21671 https://www.cve.org/CVERecord?id=CVE-2025-21671 Référence CVE CVE-2025-21673 https://www.cve.org/CVERecord?id=CVE-2025-21673 Référence CVE CVE-2025-21681 https://www.cve.org/CVERecord?id=CVE-2025-21681 Référence CVE CVE-2025-21691 https://www.cve.org/CVERecord?id=CVE-2025-21691 Référence CVE CVE-2025-21694 https://www.cve.org/CVERecord?id=CVE-2025-21694 Référence CVE CVE-2025-21705 https://www.cve.org/CVERecord?id=CVE-2025-21705 Référence CVE CVE-2025-21706 https://www.cve.org/CVERecord?id=CVE-2025-21706 Référence CVE CVE-2025-21707 https://www.cve.org/CVERecord?id=CVE-2025-21707 Référence CVE CVE-2025-21709 https://www.cve.org/CVERecord?id=CVE-2025-21709 Référence CVE CVE-2025-21713 https://www.cve.org/CVERecord?id=CVE-2025-21713 Référence CVE CVE-2025-21716 https://www.cve.org/CVERecord?id=CVE-2025-21716 Référence CVE CVE-2025-21723 https://www.cve.org/CVERecord?id=

Official advisory ↗
CERT-FR · French · CERTFR-2025-AVI-0969Multiples vulnérabilités dans les produits VMware

d?id=CVE-2025-21676 Référence CVE CVE-2025-21678 https://www.cve.org/CVERecord?id=CVE-2025-21678 Référence CVE CVE-2025-21680 https://www.cve.org/CVERecord?id=CVE-2025-21680 Référence CVE CVE-2025-21681 https://www.cve.org/CVERecord?id=CVE-2025-21681 Référence CVE CVE-2025-21682 https://www.cve.org/CVERecord?id=CVE-2025-21682 Référence CVE CVE-2025-21683 https://www.cve.org/CVERecord?id=CVE-2025-21683 Référence CVE CVE-2025-21684 https://www.cve.org/CVERecord?id=CVE-2025-21684 Référence CVE CVE-2025-21689 https://www.cve.org/CVERecord?id=CVE-2025-21689 Référence CVE CVE-2025-21690 https://www.cve.org/CVERecord?id=CVE-2025-21690 Référence CVE CVE-2025-21691 https://www.cve.org/CVERecord?id=CVE-2025-21691 Référence CVE CVE-2025-21692 https://www.cve.org/CVERecord?id=CVE-2025-21692 Référence CVE CVE-2025-21694 https://www.cve.org/CVERecord?id=CVE-2025-21694 Référence CVE CVE-2025-21697 https://www.cve.org/CVERecord?id=CVE-2025-21697 Référence CVE CVE-2025-21699 https://www.cve.org/CVERecord?id=CVE-2025-21699 Référence CVE CVE-2025-21704 https://www.cve.org/CVERecord?id=CVE-2025-21704 Référence CVE CVE-2025-21705 https://www.cve.org/CVERecord?id=CVE-2025-21705 Référence CVE CVE-2025-21706 https://www.cve.org/CVERecord?id=CVE-2025-21706 Référence CVE CVE-2025-21707 https://www.cve.org/CVERecord?id=

Official advisory ↗
CERT-FR · French · CERTFR-2025-AVI-0559Multiples vulnérabilités dans le noyau Linux d'Ubuntu

d?id=CVE-2025-21676 Référence CVE CVE-2025-21678 https://www.cve.org/CVERecord?id=CVE-2025-21678 Référence CVE CVE-2025-21680 https://www.cve.org/CVERecord?id=CVE-2025-21680 Référence CVE CVE-2025-21681 https://www.cve.org/CVERecord?id=CVE-2025-21681 Référence CVE CVE-2025-21682 https://www.cve.org/CVERecord?id=CVE-2025-21682 Référence CVE CVE-2025-21683 https://www.cve.org/CVERecord?id=CVE-2025-21683 Référence CVE CVE-2025-21684 https://www.cve.org/CVERecord?id=CVE-2025-21684 Référence CVE CVE-2025-21689 https://www.cve.org/CVERecord?id=CVE-2025-21689 Référence CVE CVE-2025-21690 https://www.cve.org/CVERecord?id=CVE-2025-21690 Référence CVE CVE-2025-21691 https://www.cve.org/CVERecord?id=CVE-2025-21691 Référence CVE CVE-2025-21692 https://www.cve.org/CVERecord?id=CVE-2025-21692 Référence CVE CVE-2025-21694 https://www.cve.org/CVERecord?id=CVE-2025-21694 Référence CVE CVE-2025-21697 https://www.cve.org/CVERecord?id=CVE-2025-21697 Référence CVE CVE-2025-21699 https://www.cve.org/CVERecord?id=CVE-2025-21699 Référence CVE CVE-2025-21704 https://www.cve.org/CVERecord?id=CVE-2025-21704 Référence CVE CVE-2025-21707 https://www.cve.org/CVERecord?id=CVE-2025-21707 Référence CVE CVE-2025-21708 https://www.cve.org/CVERecord?id=CVE-2025-21708 Référence CVE CVE-2025-21711 https://www.cve.org/CVERecord?id=

Official advisory ↗
CERT-FR · French · CERTFR-2025-AVI-0349Multiples vulnérabilités dans le noyau Linux d'Ubuntu

d?id=CVE-2025-21680 Référence CVE CVE-2025-21681 https://www.cve.org/CVERecord?id=CVE-2025-21681 Référence CVE CVE-2025-21682 https://www.cve.org/CVERecord?id=CVE-2025-21682 Référence CVE CVE-2025-21683 https://www.cve.org/CVERecord?id=CVE-2025-21683 Référence CVE CVE-2025-21684 https://www.cve.org/CVERecord?id=CVE-2025-21684 Référence CVE CVE-2025-21685 https://www.cve.org/CVERecord?id=CVE-2025-21685 Référence CVE CVE-2025-21687 https://www.cve.org/CVERecord?id=CVE-2025-21687 Référence CVE CVE-2025-21689 https://www.cve.org/CVERecord?id=CVE-2025-21689 Référence CVE CVE-2025-21690 https://www.cve.org/CVERecord?id=CVE-2025-21690 Référence CVE CVE-2025-21691 https://www.cve.org/CVERecord?id=CVE-2025-21691 Référence CVE CVE-2025-21692 https://www.cve.org/CVERecord?id=CVE-2025-21692 Référence CVE CVE-2025-21693 https://www.cve.org/CVERecord?id=CVE-2025-21693 Référence CVE CVE-2025-21694 https://www.cve.org/CVERecord?id=CVE-2025-21694 Référence CVE CVE-2025-21695 https://www.cve.org/CVERecord?id=CVE-2025-21695 Référence CVE CVE-2025-21696 https://www.cve.org/CVERecord?id=CVE-2025-21696 Référence CVE CVE-2025-21697 https://www.cve.org/CVERecord?id=CVE-2025-21697 Référence CVE CVE-2025-21699 https://www.cve.org/CVERecord?id=CVE-2025-21699 Référence CVE CVE-2025-21700 https://www.cve.org/CVERecord?id=

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2025-017246Linux の Linux Kernel における脆弱性

Linux の Linux Kernel には、不特定の脆弱性が存在します。

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
Linux: cf264e1329fb0307e044f7675849f9f38b44c11a < 7d6405c13b0d8a8367cd8df63f118b619a3f0dd2, cf264e1329fb0307e044f7675849f9f38b44c11a < 780ab8329672464984cf1344bd5c3993af0226c7, cf264e1329fb0307e044f7675849f9f38b44c11a < 97153a05077f618f7471f50a78158602badccb30, cf264e1329fb0307e044f7675849f9f38b44c11a < 5f537664e705b0bf8b7e329861f20128534f6a83, 6.5
Fixed
Linux: < 6.5, 6.6.75 ≤ 6.6.*, 6.12.12 ≤ 6.12.*, 6.13.1 ≤ 6.13.*, 6.14 ≤ *
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 10 Feb 2025 · Last source change 11 May 2026, 21:04 UTC · CWE not yet assigned

CVE recordCVE.org · 5.2
CVSS sourceNIST NVD
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-2025-2640
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceUnavailable
NVD statusNVD enriched

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

Material change intelligence

What changed after publication

View recent updates ↗

No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.

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-2025-21691 · cve.blacktree.nl