CVE-2026-98080

Filesystem read-only failure via stale relocation reference

Published Sep 25, 2026 · Updated Sep 25, 2026

Filesystem corruption in the Btrfs subsystem of Linux allows local users with administrative privileges to force a filesystem read-only. qgroup_account_snapshot() forces late relocation-root creation after commit and current roots diverge, causing the new root to reference an already-dropped metadata extent. The gate is a quota-enabled Btrfs filesystem undergoing snapshot accounting during relocation; the resulting delayed-reference failure interrupts writes and requires filesystem recovery.

CVSS severityUnavailable
Unscored
EPSS probability0.13%
Next 30 days · Oct 20, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Get started

Summary

What happened

Filesystem corruption in the Btrfs subsystem of Linux allows local users with administrative privileges to force a filesystem read-only. qgroup_account_snapshot() forces late relocation-root creation after commit and current roots diverge, causing the new root to reference an already-dropped metadata extent. The gate is a quota-enabled Btrfs filesystem undergoing snapshot accounting during relocation; the resulting delayed-reference failure interrupts writes and requires filesystem recovery.

The record

CVE
CVE-2026-98080
Published
Sep 25, 2026
Updated
Sep 25, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499.004
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Sep 25, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 25, 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=1f586802bb18892d2a6eb7d31d7fed78946d21a1
  2. Affected versionversion=204bfcda824428b3a298eae8e87875bbd435a3c1
  3. Affected versionversion=4.14.45 <4.15
  4. Affected versionversion=4.16.13 <4.17
  5. Affected versionversion=4.17
  6. Affected versionversion=4d31778aa2fa342f5f92ca4025b293a1729161d1 <203cbfb4fba590bd9b08bd36fa6d05b5d28923bf
  7. Affected versionversion=4d31778aa2fa342f5f92ca4025b293a1729161d1 <b5d5ab5a715001dd937c920ef8c5688fd4999ba1
  8. Affected versionversion=4d31778aa2fa342f5f92ca4025b293a1729161d1 <c4c78768d1a8ceb713693cc5524acbe984c31f3c
  9. Affected versionversion=4d31778aa2fa342f5f92ca4025b293a1729161d1 <cacf35832292997018837e484283f95a9301ebf5

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

The Linux Kernel Organization · Linuxversion=1f586802bb18892d2a6eb7d31d7fed78946d21a1; version=204bfcda824428b3a298eae8e87875bbd435a3c1; version=4.14.45 <4.15; version=4.16.13 <4.17; version=4.17; version=4d31778aa2fa342f5f92ca4025b293a1729161d1 <203cbfb4fba590bd9b08bd36fa6d05b5d28923bf; version=4d31778aa2fa342f5f92ca4025b293a1729161d1 <b5d5ab5a715001dd937c920ef8c5688fd4999ba1; version=4d31778aa2fa342f5f92ca4025b293a1729161d1 <c4c78768d1a8ceb713693cc5524acbe984c31f3c; version=4d31778aa2fa342f5f92ca4025b293a1729161d1 <cacf35832292997018837e484283f95a9301ebf5

Published CVSS scores

No CVSS assessment is available in this record.

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
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499.004Application or System Exploitation

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

See the directory against your own environment.

Your stack

Check the software in your environment

Get started to see how Hinoki identifies affected software and validates exploitability in your environment.

Get started