CVE-2025-38524Network attack vector

Kernel crash via completed-call recvmsg race

Published Aug 16, 2025 · Updated Aug 23, 2026

Race condition in the Linux kernel RxRPC subsystem allows remote attackers to crash the kernel via crafted RxRPC packets. In net/rxrpc/recvmsg.c, concurrent recvmsg threads can dequeue the same requeued call; one thread releases it before the other resumes under user_mutex. Reachability requires a userspace AF_RXRPC service socket with parallel recvmsg workers; successful exploitation triggers a kernel BUG and service interruption rather than data access or modification.

CVSS severity4.7
Medium
EPSS probability0.26%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Race condition in the Linux kernel RxRPC subsystem allows remote attackers to crash the kernel via crafted RxRPC packets. In net/rxrpc/recvmsg.c, concurrent recvmsg threads can dequeue the same requeued call; one thread releases it before the other resumes under user_mutex. Reachability requires a userspace AF_RXRPC service socket with parallel recvmsg workers; successful exploitation triggers a kernel BUG and service interruption rather than data access or modification.

The record

CVE
CVE-2025-38524
Published
Aug 16, 2025
Updated
Aug 23, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 16, 2025CVE publishedPublication date reported by the CVE source.
  2. Aug 23, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=248f219cb8bcbfbd7f132752d44afa2df7c241d1 <4aed0eeca58e26d752bb08b293b8dc75c6820b23
  2. Affected versionversion=248f219cb8bcbfbd7f132752d44afa2df7c241d1 <6c75a97a32a5fa2060c3dd30207e63b6914b606d
  3. Affected versionversion=248f219cb8bcbfbd7f132752d44afa2df7c241d1 <7692bde890061797f3dece0148d7859e85c55778
  4. Affected versionversion=248f219cb8bcbfbd7f132752d44afa2df7c241d1 <839fe96c15209dc2255c064bb44b636efe04f032
  5. Affected versionversion=248f219cb8bcbfbd7f132752d44afa2df7c241d1 <962fb1f651c2cf2083e0c3ef53ba69e3b96d3fbc
  6. Affected versionversion=4.9

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=248f219cb8bcbfbd7f132752d44afa2df7c241d1 <4aed0eeca58e26d752bb08b293b8dc75c6820b23; version=248f219cb8bcbfbd7f132752d44afa2df7c241d1 <6c75a97a32a5fa2060c3dd30207e63b6914b606d; version=248f219cb8bcbfbd7f132752d44afa2df7c241d1 <7692bde890061797f3dece0148d7859e85c55778; version=248f219cb8bcbfbd7f132752d44afa2df7c241d1 <839fe96c15209dc2255c064bb44b636efe04f032; version=248f219cb8bcbfbd7f132752d44afa2df7c241d1 <962fb1f651c2cf2083e0c3ef53ba69e3b96d3fbc; version=4.9

Published CVSS scores

7.0Amazon LinuxCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
6.8SUSECVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
5.5SUSECVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
4.7NVDCVSS: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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499Endpoint Denial of Service

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

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo