CVE-2025-21732

RDMA service interruption via freed lkey invalidation

Published Feb 27, 2025 · Updated May 11, 2026

Race condition in the Linux kernel RDMA/mlx5 driver allows local users to interrupt RDMA service by invalidating a freed ODP lkey. Concurrent mlx5_ib_invalidate_range and __mlx5_ib_dereg_mr operations let mlx5r_umr_update_xlt submit work after hardware frees the lkey, forcing the UMR QP into an error state. Exploitation requires local access to an mlx5 RDMA device with ODP memory registration and interrupts RDMA operations without reported data disclosure or modification.

CVSS severity4.7
Medium
EPSS probability0.14%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Race condition in the Linux kernel RDMA/mlx5 driver allows local users to interrupt RDMA service by invalidating a freed ODP lkey. Concurrent mlx5_ib_invalidate_range and __mlx5_ib_dereg_mr operations let mlx5r_umr_update_xlt submit work after hardware frees the lkey, forcing the UMR QP into an error state. Exploitation requires local access to an mlx5 RDMA device with ODP memory registration and interrupts RDMA operations without reported data disclosure or modification.

The record

CVE
CVE-2025-21732
Published
Feb 27, 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. Feb 27, 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=5.13
  2. Affected versionversion=e6fb246ccafbdfc86e0750af021628132fdbceac <5297f5ddffef47b94172ab0d3d62270002a3dcc1
  3. Affected versionversion=e6fb246ccafbdfc86e0750af021628132fdbceac <abb604a1a9c87255c7a6f3b784410a9707baf467
  4. Affected versionversion=e6fb246ccafbdfc86e0750af021628132fdbceac <b13d32786acabf70a7b04ed24b7468fc3c82977c

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.13; version=e6fb246ccafbdfc86e0750af021628132fdbceac <5297f5ddffef47b94172ab0d3d62270002a3dcc1; version=e6fb246ccafbdfc86e0750af021628132fdbceac <abb604a1a9c87255c7a6f3b784410a9707baf467; version=e6fb246ccafbdfc86e0750af021628132fdbceac <b13d32786acabf70a7b04ed24b7468fc3c82977c

Published CVSS scores

5.5OracleCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
4.7UbuntuCVSS:3.1/AV:L/AC:H/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 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.

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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