CVE-2026-45949

Local service interruption via hwrng teardown race

Published May 27, 2026 · Updated May 27, 2026

Use-after-free in the Linux kernel hwrng core allows local users to interrupt service by racing hardware RNG registration or removal. The hwrng_unregister path reads hwrng_fill outside rng_mutex, allowing concurrent teardown to stop one task twice or retain a pointer to a freed task. Exploitation requires local low-privileged access and precise timing around hardware RNG registration or removal; the documented impact is availability loss only.

CVSS severity5.5
Medium
EPSS probability0.09%
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 Linux kernel hwrng core allows local users to interrupt service by racing hardware RNG registration or removal. The hwrng_unregister path reads hwrng_fill outside rng_mutex, allowing concurrent teardown to stop one task twice or retain a pointer to a freed task. Exploitation requires local low-privileged access and precise timing around hardware RNG registration or removal; the documented impact is availability loss only.

The record

CVE
CVE-2026-45949
Published
May 27, 2026
Updated
May 27, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-362, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 27, 2026CVE publishedPublication date reported by the CVE source.
  2. May 27, 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=3.17
  2. Affected versionversion=be4000bc4644d027c519b6361f5ae3bbfc52c347 <ad38f2cdfef9a2f2899c30cad269baec5bfd4a5d
  3. Affected versionversion=be4000bc4644d027c519b6361f5ae3bbfc52c347 <cc2f39d6ac48e6e3cb2d6240bc0d6df839dd0828
  4. Affected versionversion=be4000bc4644d027c519b6361f5ae3bbfc52c347 <d5b7730f06994499632026c30e38e0317c4569e2
  5. Affected versionversion=be4000bc4644d027c519b6361f5ae3bbfc52c347 <dcf416eb88eafe1e3c0f920a14bdffd10bc4d259

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=3.17; version=be4000bc4644d027c519b6361f5ae3bbfc52c347 <ad38f2cdfef9a2f2899c30cad269baec5bfd4a5d; version=be4000bc4644d027c519b6361f5ae3bbfc52c347 <cc2f39d6ac48e6e3cb2d6240bc0d6df839dd0828; version=be4000bc4644d027c519b6361f5ae3bbfc52c347 <d5b7730f06994499632026c30e38e0317c4569e2; version=be4000bc4644d027c519b6361f5ae3bbfc52c347 <dcf416eb88eafe1e3c0f920a14bdffd10bc4d259

Published CVSS scores

5.5OracleCVSS:3.1/AV:L/AC:L/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 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')
T1499.004Endpoint Denial of Service: Application 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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