CVE-2025-39822

Service interruption via signed buffer-length conversion

Published Sep 16, 2025 · Updated Sep 16, 2025

Integer conversion in io_uring buffer commitment in Linux 6.15 through 6.16.4 allows local users to interrupt service via a large buffer. The buffer-commit path converts unsigned buf->len into a signed int while calculating this_len, so sufficiently large lengths are interpreted as negative. Local low-privileged access is required, and the published assessment limits the consequence to availability without confidentiality or integrity loss.

CVSS severity5.5
Medium
EPSS probability0.13%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Integer conversion in io_uring buffer commitment in Linux 6.15 through 6.16.4 allows local users to interrupt service via a large buffer. The buffer-commit path converts unsigned buf->len into a signed int while calculating this_len, so sufficiently large lengths are interpreted as negative. Local low-privileged access is required, and the published assessment limits the consequence to availability without confidentiality or integrity loss.

The record

CVE
CVE-2025-39822
Published
Sep 16, 2025
Updated
Sep 16, 2025
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 16, 2025CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 2025Record 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=6.12
  2. Affected versionversion=ae98dbf43d755b4e111fcd086e53939bef3e9a1a <c64eff368ac676e8540344d27a3de47e0ad90d21
  3. Affected versionversion=ae98dbf43d755b4e111fcd086e53939bef3e9a1a <f4f411c068402c370c4f9a9d4950a97af97bbbb1

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=6.12; version=ae98dbf43d755b4e111fcd086e53939bef3e9a1a <c64eff368ac676e8540344d27a3de47e0ad90d21; version=ae98dbf43d755b4e111fcd086e53939bef3e9a1a <f4f411c068402c370c4f9a9d4950a97af97bbbb1

Published CVSS scores

5.5CISA-ADPCVSS: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.

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

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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