CVE-2025-21661

Service interruption via missing lookup-table cleanup

Published Jan 21, 2025 · Updated Aug 5, 2026

Memory leaks in the gpio-virtuser driver in Linux 6.11 through 6.12.9 allow local users to interrupt service through configfs. The driver creates a lookup table but omits gpio_virtuser_remove_lookup_table() on probe and registration failure paths; live-state toggles also retain lookup_table->dev_id. Local low-privilege access to the virtuser configfs interface is required; stale tables block later probes, and repeated toggles consume kernel memory.

CVSS severity7.8
High
EPSS probability0.19%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Memory leaks in the gpio-virtuser driver in Linux 6.11 through 6.12.9 allow local users to interrupt service through configfs. The driver creates a lookup table but omits gpio_virtuser_remove_lookup_table() on probe and registration failure paths; live-state toggles also retain lookup_table->dev_id. Local low-privilege access to the virtuser configfs interface is required; stale tables block later probes, and repeated toggles consume kernel memory.

The record

CVE
CVE-2025-21661
Published
Jan 21, 2025
Updated
Aug 5, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-401, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jan 21, 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=6.11
  2. Affected versionversion=91581c4b3f29e2e22aeb1a62e842d529ca638b2d <a619cba8c69c434258ff4101d463322cd63e1bdc
  3. Affected versionversion=91581c4b3f29e2e22aeb1a62e842d529ca638b2d <d72d0126b1f6981f6ce8b4247305f359958c11b5

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=6.11; version=91581c4b3f29e2e22aeb1a62e842d529ca638b2d <a619cba8c69c434258ff4101d463322cd63e1bdc; version=91581c4b3f29e2e22aeb1a62e842d529ca638b2d <d72d0126b1f6981f6ce8b4247305f359958c11b5

Published CVSS scores

5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
7.8Linux kernel CNACVSS: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-401Missing Release of Memory after Effective Lifetime
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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