---
title: "CVE-2026-98991: Linux Kernel - Use After Free"
description: "Linux kernel contains a use-after-free vulnerability caused by multiple queuing of mounts in notify_list due to missing checks in mnt_notify_add(), letting attackers cause kernel memory corruption, exploit requires mounts with MNT_SHRINKABLE flag and specific namespace conditions."
url: https://panop.io/threat-heartbeat/CVE-2026-98991/
---

# CVE-2026-98991 Linux Kernel - Use After Free

Linux kernel contains a use-after-free vulnerability caused by multiple queuing of mounts in notify\_list due to missing checks in mnt\_notify\_add(), letting attackers cause kernel memory corruption, exploit requires mounts with MNT\_SHRINKABLE flag and specific namespace conditions.

CVSS base score 7.8 /10

High

CISA KEV

Not listed

Public exploit

None known

EPSS

0.21% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-98991)

## Details

Type

Use After Free

Impact

Denial Of Service

CVSS vector

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

Published

23 October 2026

Updated

25 October 2026

## Vendor fix

Update to the latest Linux kernel version containing the fix for mount notification queuing.

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-2026-98991](https://nvd.nist.gov/vuln/detail/CVE-2026-98991)
- [https://git.kernel.org/stable/c/acbe9e4418e2ef7bef1a12e62e0e7d6145a15190](https://git.kernel.org/stable/c/acbe9e4418e2ef7bef1a12e62e0e7d6145a15190)
- [https://git.kernel.org/stable/c/bd2feb7796b6585938a4241e7b7c4148a6f7b762](https://git.kernel.org/stable/c/bd2feb7796b6585938a4241e7b7c4148a6f7b762)
- [https://git.kernel.org/stable/c/702ff3fe499876e09c45558a05366d21a5bc41ab](https://git.kernel.org/stable/c/702ff3fe499876e09c45558a05366d21a5bc41ab)

[← All CVEs](https://panop.io/threat-heartbeat/)

## 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

Panop answers these inside your environment, for this CVE and every other finding.

[Book a demo](https://panop.io/demo)