CVE-2026-90260

Filesystem corruption via premature extent-buffer zeroing

Published Sep 17, 2026 · Updated Sep 18, 2026

Memory corruption in btrfs in Linux allows local users to corrupt extent trees by stressing a zoned filesystem under concurrent activity. btree_csum_one_bio() zeroes a freed-but-dirty extent buffer's own folios while later code can still read its header, causing btrfs_free_tree_block() to free bytenr 0. Exploitation requires a zoned btrfs filesystem and a timing-sensitive reuse path; consequences include an assertion failure, filesystem abort, or extent-tree corruption.

CVSS severity5.3
Medium
EPSS probability0.17%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Memory corruption in btrfs in Linux allows local users to corrupt extent trees by stressing a zoned filesystem under concurrent activity. btree_csum_one_bio() zeroes a freed-but-dirty extent buffer's own folios while later code can still read its header, causing btrfs_free_tree_block() to free bytenr 0. Exploitation requires a zoned btrfs filesystem and a timing-sensitive reuse path; consequences include an assertion failure, filesystem abort, or extent-tree corruption.

The record

CVE
CVE-2026-90260
Published
Sep 17, 2026
Updated
Sep 18, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1485
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 17, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 18, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=6.8
  2. Affected versionversion=aa6313e6ff2bfbf736a2739047bba355d8241584 <92484ad014f2e2b0e0e7bbc1610951e978cf557c
  3. Affected versionversion=aa6313e6ff2bfbf736a2739047bba355d8241584 <98e3747587f9f87f010d8d7e55786216249a94af
  4. Affected versionversion=aa6313e6ff2bfbf736a2739047bba355d8241584 <db4b9eefc8ee0bcaeee4d5e6a7313905f6a2fe7c

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=6.8; version=aa6313e6ff2bfbf736a2739047bba355d8241584 <92484ad014f2e2b0e0e7bbc1610951e978cf557c; version=aa6313e6ff2bfbf736a2739047bba355d8241584 <98e3747587f9f87f010d8d7e55786216249a94af; version=aa6313e6ff2bfbf736a2739047bba355d8241584 <db4b9eefc8ee0bcaeee4d5e6a7313905f6a2fe7c

Published CVSS scores

5.3Amazon LinuxCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Activity data is delayed. The latest report is Sep 28, 2026.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1485Data Destruction

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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