CVE-2026-80530Public exploit

Local privilege escalation via premature reflink clearing

Published Aug 26, 2026 · Updated Aug 26, 2026

Improper reflink flag clearing in the Linux XFS exchange-range path allows local users to overwrite reflink-shared file data. With INO1_WRITTEN set, xfs_exchmaps_can_skip_mapping() omits mappings while cleanup clears the reflink flag from an inode that still owns shared extents. A low-privileged user needs writable exchange files on an XFS filesystem with the experimental exchange-range feature enabled; later writes bypass copy-on-write and can alter readable privileged files.

CVSS severity7.1
High
EPSS probability0.13%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper reflink flag clearing in the Linux XFS exchange-range path allows local users to overwrite reflink-shared file data. With INO1_WRITTEN set, xfs_exchmaps_can_skip_mapping() omits mappings while cleanup clears the reflink flag from an inode that still owns shared extents. A low-privileged user needs writable exchange files on an XFS filesystem with the experimental exchange-range feature enabled; later writes bypass copy-on-write and can alter readable privileged files.

The record

CVE
CVE-2026-80530
Published
Aug 26, 2026
Updated
Aug 26, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 26, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 26, 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=6.10
  2. Affected versionversion=966ceafc7a437105ecfe1cadb3747b2965a260ca <03c9c9116e6da641424681f705698d7f5e2128e0
  3. Affected versionversion=966ceafc7a437105ecfe1cadb3747b2965a260ca <0f27b22343b63e10773e6781344640c2c753eec3
  4. Affected versionversion=966ceafc7a437105ecfe1cadb3747b2965a260ca <2efbd8890b53f4756fdc7b0ef346fa514ffb7d66
  5. Affected versionversion=966ceafc7a437105ecfe1cadb3747b2965a260ca <b2d5a81dae385333f9734910277fbf94c78bd17f

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=6.10; version=966ceafc7a437105ecfe1cadb3747b2965a260ca <03c9c9116e6da641424681f705698d7f5e2128e0; version=966ceafc7a437105ecfe1cadb3747b2965a260ca <0f27b22343b63e10773e6781344640c2c753eec3; version=966ceafc7a437105ecfe1cadb3747b2965a260ca <2efbd8890b53f4756fdc7b0ef346fa514ffb7d66; version=966ceafc7a437105ecfe1cadb3747b2965a260ca <b2d5a81dae385333f9734910277fbf94c78bd17f

Published CVSS scores

4.7Amazon LinuxCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:N
7.1LinuxCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

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.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

T1068Exploitation for Privilege Escalation

Public exploit references

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

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