CVE-2025-21934

Local privilege escalation via RapidIO use-after-free

Published Apr 1, 2025 · Updated Aug 5, 2026

Use-after-free in the RapidIO mport driver in Linux 4.6 through 6.13.6 allows local users to corrupt kernel memory via RIO_DEV_ADD. On device_register() failure, rio_add_net() frees the registered device with kfree() instead of put_device() and leaves mport->net dangling. Access to /dev/rio_mportN is required; Ubuntu restricts it to root with mode 0600 by default, while delegated access enables privilege escalation or a kernel panic.

CVSS severity7.8
High
EPSS probability0.21%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in the RapidIO mport driver in Linux 4.6 through 6.13.6 allows local users to corrupt kernel memory via RIO_DEV_ADD. On device_register() failure, rio_add_net() frees the registered device with kfree() instead of put_device() and leaves mport->net dangling. Access to /dev/rio_mportN is required; Ubuntu restricts it to root with mode 0600 by default, while delegated access enables privilege escalation or a kernel panic.

The record

CVE
CVE-2025-21934
Published
Apr 1, 2025
Updated
Aug 5, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-416, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 1, 2025CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 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=4.6
  2. Affected versionversion=e8de370188d098bb49483c287b44925957c3c9b6 <22e4977141dfc6d109bf29b495bf2187b4250990
  3. Affected versionversion=e8de370188d098bb49483c287b44925957c3c9b6 <2537f01d57f08c527e40bbb5862aa6ff43344898
  4. Affected versionversion=e8de370188d098bb49483c287b44925957c3c9b6 <88ddad53e4cfb6de861c6d4fb7b25427f46baed5
  5. Affected versionversion=e8de370188d098bb49483c287b44925957c3c9b6 <a5f5e520e8fbc6294020ff8afa36f684d92c6e6a
  6. Affected versionversion=e8de370188d098bb49483c287b44925957c3c9b6 <b2ef51c74b0171fde7eb69b6152d3d2f743ef269
  7. Affected versionversion=e8de370188d098bb49483c287b44925957c3c9b6 <cdd9f58f7fe41a55fae4305ea51fc234769fd466
  8. Affected versionversion=e8de370188d098bb49483c287b44925957c3c9b6 <d4ec862ce80f64db923a1d942b5d11cf6fc87d36
  9. Affected versionversion=e8de370188d098bb49483c287b44925957c3c9b6 <f0aa4ee1cbbf7789907e5a3f6810de01c146c211

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=4.6; version=e8de370188d098bb49483c287b44925957c3c9b6 <22e4977141dfc6d109bf29b495bf2187b4250990; version=e8de370188d098bb49483c287b44925957c3c9b6 <2537f01d57f08c527e40bbb5862aa6ff43344898; version=e8de370188d098bb49483c287b44925957c3c9b6 <88ddad53e4cfb6de861c6d4fb7b25427f46baed5; version=e8de370188d098bb49483c287b44925957c3c9b6 <a5f5e520e8fbc6294020ff8afa36f684d92c6e6a; version=e8de370188d098bb49483c287b44925957c3c9b6 <b2ef51c74b0171fde7eb69b6152d3d2f743ef269; version=e8de370188d098bb49483c287b44925957c3c9b6 <cdd9f58f7fe41a55fae4305ea51fc234769fd466; version=e8de370188d098bb49483c287b44925957c3c9b6 <d4ec862ce80f64db923a1d942b5d11cf6fc87d36; version=e8de370188d098bb49483c287b44925957c3c9b6 <f0aa4ee1cbbf7789907e5a3f6810de01c146c211

Published CVSS scores

7.8UbuntuCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
7.8Linux kernel CVE teamCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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

CWE-416Use After Free
T1068Exploitation for Privilege Escalation

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

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Your stack

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