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Full vulnerability report · 2026
CVE-2026-64216High confidence

netfs: Fix potential UAF in netfs_unlock_abandoned_read_pages()

Linux · Linux

9.8CriticalCVSS 3.1
Recommended action
Within 72 hours

Critical technical impact with a remotely reachable, unauthenticated path; no CISA KEV confirmation is currently recorded.

Patch available
Distribution package intelligence

Ubuntu vendor package status

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

13 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 archivelinux-aws-6.14Affected, 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-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-azure-fde-6.14Affected, 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-nvidia-6.14Affected, 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-gcp-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-hwe-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-lowlatency-hwe-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-nvidia-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-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-oracle-6.14Affected, 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
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-2026-48624

No EUVD known-exploited evidence

In the Linux kernel, the following vulnerability has been resolved: netfs: Fix potential UAF in netfs_unlock_abandoned_read_pages() netfs_unlock_abandoned_read_pages(rreq) accesses the index of the folios it is wanting to unlock and compares that to rreq->no_unlock_folio so that it doesn't unlock a folio being read for netfs_perform_write() or netfs_write_begin(). However, given that netfs_unlock_abandoned_read_pages() is called _after_ NETFS_RREQ_IN_PROGRESS is cleared, the one folio that it's not allowed to dereference is the one specified by ->no_unlock_folio as ownership immediately reverts to the caller. Fix this by storing the folio pointer instead and using that rather than the index. Also fix netfs_unlock_read_folio() where the same applies.

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
9.8 · CVSS 3.1
Advisory evidence
No linked advisory details stored yet
Recommended actionWithin 72 hours

Critical technical impact with a remotely reachable, unauthenticated path; no CISA KEV confirmation is currently recorded.

Patch available
01

What, why and how

In the Linux kernel, the following vulnerability has been resolved: netfs: Fix potential UAF in netfs_unlock_abandoned_read_pages() netfs_unlock_abandoned_read_pages(rreq) accesses the index of the folios it is wanting to unlock and compares that to rreq->no_unlock_folio so that it doesn't unlock a folio being read for netfs_perform_write() or netfs_write_begin(). However, given that netfs_unlock_abandoned_read_pages() is called _after_ NETFS_RREQ_IN_PROGRESS is cleared, the one folio that it's not allowed to dereference is the one specified by ->no_unlock_folio as ownership immediately reverts to the caller. Fix this by storing the folio pointer instead and using that rather than the index. Also fix netfs_unlock_read_folio() where the same applies.

What

In the Linux kernel, the following vulnerability has been resolved: netfs: Fix potential UAF in netfs_unlock_abandoned_read_pages() netfs_unlock_abandoned_read_pages(rreq) accesses the index of the folios it is wanting to unlock and compares that to rreq->no_unlock_folio so that it doesn't unlock a folio being read for netfs_perform_write() or netfs_write_begin(). However, given that netfs_unlock_abandoned_read_pages() is called _after_ NETFS_RREQ_IN_PROGRESS is cleared, the one folio that it's not allowed to dereference is the one specified by ->no_unlock_folio as ownership immediately reverts to the caller. Fix this by storing the folio pointer instead and using that rather than the index. Also fix netfs_unlock_read_folio() where the same applies.

Why

The program can continue using memory after it has been released, producing unsafe and attacker-influenceable behaviour.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. 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: netfs: Fix potential UAF in netfs_unlock_abandoned_read_pages() netfs_unlock_abandoned_read_pages(rreq) accesses the index of the folios it is wanting to unlock and compares that to rreq->no_unlock_folio so that it doesn't unlock a folio being read for netfs_perform_write() or netfs_write_begin(). However, given that netfs_unlock_abandoned_read_pages() is called _after_ NETFS_RREQ_IN_PROGRESS is cleared, the one folio that it's not allowed to dereference is the one specified by ->no_unlock_folio as ownership immediately reverts to the caller. Fix this by storing the folio pointer instead and using that rather than the index. Also fix netfs_unlock_read_folio() where the same applies.

Why

The program can continue using memory after it has been released, producing unsafe and attacker-influenceable behaviour.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. 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
a network path → Use After Free → cause the confidentiality, integrity or availability impact described by the vendor
Attack surface
Network
Privileges required
None: unauthenticated exploitation is possible
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: a standard category for the underlying weakness.
CWE-416 ↗

CWE-416: Use After Free. The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory belongs to the code that operates on the new pointer.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

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

AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRNonePrivileges required: The attacker does not need an account or existing privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CHighConfidentiality impact: A successful attack can cause a major loss.IHighIntegrity impact: A successful attack can cause a major loss.AHighAvailability impact: A successful attack can cause a major loss.
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.
NetworkUnauthenticatedCWE-416
A

Official authority intelligence

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

ENISA EUVD · EUVD-2026-48624Official EUVD mapping

In the Linux kernel, the following vulnerability has been resolved: netfs: Fix potential UAF in netfs_unlock_abandoned_read_pages() netfs_unlock_abandoned_read_pages(rreq) accesses the index of the folios it is wanting to unlock and compares that to rreq->no_unlock_folio so that it doesn't unlock a folio being read for netfs_perform_write() or netfs_write_begin(). However, given that netfs_unlock_abandoned_read_pages() is called _after_ NETFS_RREQ_IN_PROGRESS is cleared, the one folio that it's not allowed to dereference is the one specified by ->no_unlock_folio as ownership immediately reverts to the caller. Fix this by storing the folio pointer instead and using that rather than the index. Also fix netfs_unlock_read_folio() where the same applies.

Official EUVD record ↗
BSI · German · WID-SEC-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 ↗
Cyber Security Agency of Singapore · English · CSA-SB-20260729Security Bulletin 29 Jul 2026

The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 29 Jul 2026, published on 29 July 2026. Open the linked bulletin for the product, severity and reference information published in that issue.

Official advisory ↗
CERT-FR · French · CERTFR-2026-AVI-1162Multiples vulnérabilités dans le noyau Linux d'Ubuntu

d?id=CVE-2026-64207 Référence CVE CVE-2026-64208 https://www.cve.org/CVERecord?id=CVE-2026-64208 Référence CVE CVE-2026-64209 https://www.cve.org/CVERecord?id=CVE-2026-64209 Référence CVE CVE-2026-64210 https://www.cve.org/CVERecord?id=CVE-2026-64210 Référence CVE CVE-2026-64211 https://www.cve.org/CVERecord?id=CVE-2026-64211 Référence CVE CVE-2026-64212 https://www.cve.org/CVERecord?id=CVE-2026-64212 Référence CVE CVE-2026-64213 https://www.cve.org/CVERecord?id=CVE-2026-64213 Référence CVE CVE-2026-64214 https://www.cve.org/CVERecord?id=CVE-2026-64214 Référence CVE CVE-2026-64215 https://www.cve.org/CVERecord?id=CVE-2026-64215 Référence CVE CVE-2026-64216 https://www.cve.org/CVERecord?id=CVE-2026-64216 Référence CVE CVE-2026-64217 https://www.cve.org/CVERecord?id=CVE-2026-64217 Référence CVE CVE-2026-64218 https://www.cve.org/CVERecord?id=CVE-2026-64218 Référence CVE CVE-2026-64219 https://www.cve.org/CVERecord?id=CVE-2026-64219 Référence CVE CVE-2026-64220 https://www.cve.org/CVERecord?id=CVE-2026-64220 Référence CVE CVE-2026-64221 https://www.cve.org/CVERecord?id=CVE-2026-64221 Référence CVE CVE-2026-64222 https://www.cve.org/CVERecord?id=CVE-2026-64222 Référence CVE CVE-2026-64223 https://www.cve.org/CVERecord?id=CVE-2026-64223 Référence CVE CVE-2026-64224 https://www.cve.org/CVERecord?id=

Official advisory ↗
CERT-FR · French · CERTFR-2026-AVI-1119Multiples vulnérabilités dans le noyau Linux de Debian

De multiples vulnérabilités ont été découvertes dans le noyau Linux de Debian. Elles permettent à un attaquant de provoquer une élévation de privilèges, une atteinte à la confidentialité des données et un déni de service.

Official advisory ↗
CERT-FR · French · CERTFR-2026-AVI-1066Multiples vulnérabilités dans le noyau Linux d'Ubuntu

d?id=CVE-2026-64186 Référence CVE CVE-2026-64208 https://www.cve.org/CVERecord?id=CVE-2026-64208 Référence CVE CVE-2026-64209 https://www.cve.org/CVERecord?id=CVE-2026-64209 Référence CVE CVE-2026-64210 https://www.cve.org/CVERecord?id=CVE-2026-64210 Référence CVE CVE-2026-64211 https://www.cve.org/CVERecord?id=CVE-2026-64211 Référence CVE CVE-2026-64212 https://www.cve.org/CVERecord?id=CVE-2026-64212 Référence CVE CVE-2026-64213 https://www.cve.org/CVERecord?id=CVE-2026-64213 Référence CVE CVE-2026-64214 https://www.cve.org/CVERecord?id=CVE-2026-64214 Référence CVE CVE-2026-64215 https://www.cve.org/CVERecord?id=CVE-2026-64215 Référence CVE CVE-2026-64216 https://www.cve.org/CVERecord?id=CVE-2026-64216 Référence CVE CVE-2026-64217 https://www.cve.org/CVERecord?id=CVE-2026-64217 Référence CVE CVE-2026-64218 https://www.cve.org/CVERecord?id=CVE-2026-64218 Référence CVE CVE-2026-64219 https://www.cve.org/CVERecord?id=CVE-2026-64219 Référence CVE CVE-2026-64220 https://www.cve.org/CVERecord?id=CVE-2026-64220 Référence CVE CVE-2026-64221 https://www.cve.org/CVERecord?id=CVE-2026-64221 Référence CVE CVE-2026-64222 https://www.cve.org/CVERecord?id=CVE-2026-64222 Référence CVE CVE-2026-64223 https://www.cve.org/CVERecord?id=CVE-2026-64223 Référence CVE CVE-2026-64224 https://www.cve.org/CVERecord?id=

Official advisory ↗
CERT-FR · French · CERTFR-2026-AVI-0954Multiples vulnérabilités dans le noyau Linux d'Ubuntu

d?id=CVE-2026-64186 Référence CVE CVE-2026-64208 https://www.cve.org/CVERecord?id=CVE-2026-64208 Référence CVE CVE-2026-64209 https://www.cve.org/CVERecord?id=CVE-2026-64209 Référence CVE CVE-2026-64210 https://www.cve.org/CVERecord?id=CVE-2026-64210 Référence CVE CVE-2026-64211 https://www.cve.org/CVERecord?id=CVE-2026-64211 Référence CVE CVE-2026-64212 https://www.cve.org/CVERecord?id=CVE-2026-64212 Référence CVE CVE-2026-64213 https://www.cve.org/CVERecord?id=CVE-2026-64213 Référence CVE CVE-2026-64214 https://www.cve.org/CVERecord?id=CVE-2026-64214 Référence CVE CVE-2026-64215 https://www.cve.org/CVERecord?id=CVE-2026-64215 Référence CVE CVE-2026-64216 https://www.cve.org/CVERecord?id=CVE-2026-64216 Référence CVE CVE-2026-64217 https://www.cve.org/CVERecord?id=CVE-2026-64217 Référence CVE CVE-2026-64218 https://www.cve.org/CVERecord?id=CVE-2026-64218 Référence CVE CVE-2026-64219 https://www.cve.org/CVERecord?id=CVE-2026-64219 Référence CVE CVE-2026-64220 https://www.cve.org/CVERecord?id=CVE-2026-64220 Référence CVE CVE-2026-64221 https://www.cve.org/CVERecord?id=CVE-2026-64221 Référence CVE CVE-2026-64222 https://www.cve.org/CVERecord?id=CVE-2026-64222 Référence CVE CVE-2026-64223 https://www.cve.org/CVERecord?id=CVE-2026-64223 Référence CVE CVE-2026-64224 https://www.cve.org/CVERecord?id=

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2026-027857LinuxのLinux Kernelにおける解放済みメモリの使用に関する脆弱性

Linuxカーネルにおいて、以下の脆弱性が修正されました。 netfs: netfs_unlock_abandoned_read_pages() における潜在的な使用後解放（UAF）問題の修正です。netfs_unlock_abandoned_read_pages(rreq) は、アンロックしようとしているフォリオのインデックスにアクセスし、その値を rreq-＞no_unlock_folio と比較することで、netfs_perform_write() または netfs_write_begin() のために読み込み中のフォリオをアンロックしないように制御しています。しかしながら、netfs_unlock_abandoned_read_pages() は NETFS_RREQ_IN_PROGRESS フラグがクリアされた後に呼び出されるため、参照禁止となるフォリオは no_unlock_folio に指定されたものであり、その所有権は直ちに呼び出し元に戻ります。これを修正するために、インデックスではなくフォリオポインタ自体を保持し、それを使用するよう変更しました。同様の問題がある netfs_unlock_read_folio() も修正されています。

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: ee4cdf7ba857a894ad1650d6ab77669cbbfa329e < d4ae8dba90b89e7bb4d1045d1cb26afbaf13ee5c, ee4cdf7ba857a894ad1650d6ab77669cbbfa329e < 6080fa3ecfbb4448a3b47368629534c09b6ec750, ee4cdf7ba857a894ad1650d6ab77669cbbfa329e < 3866d015f33aeedf81338dd99154703bef33faef, ee4cdf7ba857a894ad1650d6ab77669cbbfa329e < dbe556972100fabb8e5a1b3d2163831ff07b1e8e, 6.12
Fixed
Linux: < 6.12, 6.12.106 ≤ 6.12.*, 6.18.34 ≤ 6.18.*, 7.0.11 ≤ 7.0.*, 7.1 ≤ *
Action
Review the linked authoritative reference and apply the recorded fixed release appropriate to the affected product branch.
Workaround
No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04

Evidence and provenance

Published 24 Jul 2026 · Last source change 27 Aug 2026, 12:39 UTC · CWE-416 · Use After Free

CVE recordCVE.org · 5.2
CVSS sourceCNA
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-2026-48624
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceNIST NVD
NVD statusNVD modified after enrichment

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates ↗
  1. Affected versionsThe structured affected or fixed version information changed.
    Before
    ee4cdf7ba857a894ad1650d6ab77669cbbfa329e < 6080fa3ecfbb4448a3b47368629534c09b6ec750; ee4cdf7ba857a894ad1650d6ab77669cbbfa329e < 3866d015f33aeedf81338dd99154703bef33faef; ee4cdf7ba857a894ad1650d6ab77669cbbfa329e < dbe556972100fabb8e5a1b3d2163831ff07b1e8e; 6.12 · Fixed: < 6.12; 6.18.34 ≤ 6.18.*; 7.0.11 ≤ 7.0.*; 7.1 ≤ *
    After
    ee4cdf7ba857a894ad1650d6ab77669cbbfa329e < d4ae8dba90b89e7bb4d1045d1cb26afbaf13ee5c; ee4cdf7ba857a894ad1650d6ab77669cbbfa329e < 6080fa3ecfbb4448a3b47368629534c09b6ec750; ee4cdf7ba857a894ad1650d6ab77669cbbfa329e < 3866d015f33aeedf81338dd99154703bef33faef; ee4cdf7ba857a894ad1650d6ab77669cbbfa329e < dbe556972100fabb8e5a1b3d2163831ff07b1e8e; 6.12 · Fixed: < 6.12; 6.12.106 ≤ 6.12.*; 6.18.34 ≤ 6.18.*; 7.0.11 ≤ 7.0.*; 7.1 ≤ *
    CNA ↗
Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
Fixed release or patch reference recorded
ENISA EUVD · EUVD-2026-48624↗Patch or update reference↗Patch or update reference↗Patch or update reference↗CVE authority or vendor reference↗Official CVE record (CNA and ADP data)↗NVD record↗
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-2026-64216 · cve.blacktree.nl