---
title: "CVE-2026-89649: Linux kernel CephFS - Information Disclosure"
description: "Linux kernel CephFS contains an information disclosure vulnerability caused by missing bounds check on the last xattr value length in __build_xattrs(), letting a malicious metadata server disclose adjacent kernel heap bytes to local users via getxattr(2), exploit requires local user access."
url: https://panop.io/threat-heartbeat/CVE-2026-89649/
---

# CVE-2026-89649 Linux kernel CephFS - Information Disclosure

Linux kernel CephFS contains an information disclosure vulnerability caused by missing bounds check on the last xattr value length in \_\_build\_xattrs(), letting a malicious metadata server disclose adjacent kernel heap bytes to local users via getxattr(2), exploit requires local user access.

CVSS base score 9.1 /10

Critical

CISA KEV

Not listed

Public exploit

None known

Authentication

Not required

EPSS

0.68% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-89649)

## Details

Type

Information Disclosure

Impact

Information Disclosure

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H

Published

11 September 2026

Updated

15 October 2026

## Vendor fix

Update to the latest Linux kernel version containing the fix for this vulnerability.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

## References

- [https://nvd.nist.gov/vuln/detail/CVE-2026-89649](https://nvd.nist.gov/vuln/detail/CVE-2026-89649)
- [https://git.kernel.org/stable/c/848b80ca6b410f350d08b8ac19a00ef88223f2ea](https://git.kernel.org/stable/c/848b80ca6b410f350d08b8ac19a00ef88223f2ea)
- [https://git.kernel.org/stable/c/cb0cd79ae80476d1bc06bd9678484b6736f19588](https://git.kernel.org/stable/c/cb0cd79ae80476d1bc06bd9678484b6736f19588)
- [https://git.kernel.org/stable/c/1dd356310b1660215f9a3626580bf8b363ef981e](https://git.kernel.org/stable/c/1dd356310b1660215f9a3626580bf8b363ef981e)
- [https://git.kernel.org/stable/c/38be2f3c41ecaba58bb92dc16603e09ba9fd64f1](https://git.kernel.org/stable/c/38be2f3c41ecaba58bb92dc16603e09ba9fd64f1)
- [https://git.kernel.org/stable/c/68d541754d6cd3bb98d1fd8314f57e5eb533557d](https://git.kernel.org/stable/c/68d541754d6cd3bb98d1fd8314f57e5eb533557d)
- [https://git.kernel.org/stable/c/b12b3320c81fd72ab36388fb2445fec9c3038f10](https://git.kernel.org/stable/c/b12b3320c81fd72ab36388fb2445fec9c3038f10)
- [https://git.kernel.org/stable/c/01e3f19c301d492e12f16b3b463ac14d7cf3ebe7](https://git.kernel.org/stable/c/01e3f19c301d492e12f16b3b463ac14d7cf3ebe7)
- [https://git.kernel.org/stable/c/61f085cb8976c9cebc90e1a8933e4cc1ad8b0fce](https://git.kernel.org/stable/c/61f085cb8976c9cebc90e1a8933e4cc1ad8b0fce)

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## What this record can't tell you

- Whether you run the affected software, and where
- Whether an attacker can actually reach and exploit it
- The misconfigurations that never get a CVE number
- What it would cost the business, ranked into what to fix first

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