CVE-2022-49579

Availability loss via unsynchronized multipath policy reads

Published Feb 26, 2025 · Updated May 11, 2026

A race condition in Linux kernel IPv4 multipath routing allows local users to cause availability loss during concurrent hash-policy updates. The route and mlxsw routing paths read sysctl_fib_multipath_hash_policy without READ_ONCE while a sysctl writer can change it concurrently. Exploitation requires low-privileged local access and precise timing; public sources do not identify whether the resulting failure is a hang, crash, or reboot.

CVSS severity4.7
Medium
EPSS probability0.18%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

A race condition in Linux kernel IPv4 multipath routing allows local users to cause availability loss during concurrent hash-policy updates. The route and mlxsw routing paths read sysctl_fib_multipath_hash_policy without READ_ONCE while a sysctl writer can change it concurrently. Exploitation requires low-privileged local access and precise timing; public sources do not identify whether the resulting failure is a hang, crash, or reboot.

The record

CVE
CVE-2022-49579
Published
Feb 26, 2025
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-362, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 26, 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

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=4.12
  2. Affected versionversion=bf4e0a3db97eb882368fd82980b3b1fa0b5b9778 <21fb844bc1dc1461f5038d655aa1a14f39e13049
  3. Affected versionversion=bf4e0a3db97eb882368fd82980b3b1fa0b5b9778 <7998c12a08c97cc26660532c9f90a34bd7d8da5a
  4. Affected versionversion=bf4e0a3db97eb882368fd82980b3b1fa0b5b9778 <918ee6592ab9a2ff5316d06cfd4aaef60ccabec6

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=4.12; version=bf4e0a3db97eb882368fd82980b3b1fa0b5b9778 <21fb844bc1dc1461f5038d655aa1a14f39e13049; version=bf4e0a3db97eb882368fd82980b3b1fa0b5b9778 <7998c12a08c97cc26660532c9f90a34bd7d8da5a; version=bf4e0a3db97eb882368fd82980b3b1fa0b5b9778 <918ee6592ab9a2ff5316d06cfd4aaef60ccabec6

Published CVSS scores

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 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-362Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
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

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Your stack

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