CVE-2025-40246

Service interruption via XFS symlink repair over-read

Published Dec 4, 2025 · Updated May 11, 2026

Out-of-bounds read in Linux kernel XFS symlink repair from 6.10 allows local users to interrupt service through malformed XFS metadata. The xrep_symlink_salvage_inline path bounds a copy by the data-fork size instead of xfs_ifork::if_bytes, so it reads beyond the in-core buffer. The demonstrated path runs through xfs_scrub as UID 0 and requires an XFS inline symlink whose fork allocation exceeds its buffer length.

CVSS severity5.5
Medium
EPSS probability0.20%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds read in Linux kernel XFS symlink repair from 6.10 allows local users to interrupt service through malformed XFS metadata. The xrep_symlink_salvage_inline path bounds a copy by the data-fork size instead of xfs_ifork::if_bytes, so it reads beyond the in-core buffer. The demonstrated path runs through xfs_scrub as UID 0 and requires an XFS inline symlink whose fork allocation exceeds its buffer length.

The record

CVE
CVE-2025-40246
Published
Dec 4, 2025
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Dec 4, 2025CVE publishedPublication date reported by the CVE source.
  2. May 11, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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

  1. Affected versionversion=2651923d8d8db00a57665822f017fa7c76758044 <678e1cc2f482e0985a0613ab4a5bf89c497e5acc
  2. Affected versionversion=2651923d8d8db00a57665822f017fa7c76758044 <7c2d68e091584149fe89bcbaf9b99b3162d46ee7
  3. Affected versionversion=2651923d8d8db00a57665822f017fa7c76758044 <81a8685cac4bf081c93a7df591644f4f80240bb9
  4. Affected versionversion=6.10

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=2651923d8d8db00a57665822f017fa7c76758044 <678e1cc2f482e0985a0613ab4a5bf89c497e5acc; version=2651923d8d8db00a57665822f017fa7c76758044 <7c2d68e091584149fe89bcbaf9b99b3162d46ee7; version=2651923d8d8db00a57665822f017fa7c76758044 <81a8685cac4bf081c93a7df591644f4f80240bb9; version=6.10

Published CVSS scores

5.5SUSECVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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.

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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 exploitUnconfirmed

Weakness, pattern, technique

T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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