CVE-2026-43244Public exploit

Local denial of service via empty KCM fragment

Published May 6, 2026 · Updated May 6, 2026

A denial of service in affected Linux Kernel releases allows local users to interrupt service through a crafted KCM SOCK_SEQPACKET send. After MAX_SKB_FRAGS fills, kcm_sendmsg() links a new skb before copying user data and leaves that zero-fragment tail linked when the copy fails. Completing the saved partial message with a zero-length write makes kcm_write_msgs() hit WARN_ON; a system crash requires warning-to-panic behavior.

CVSS severity5.5
Medium
EPSS probability0.12%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

A denial of service in affected Linux Kernel releases allows local users to interrupt service through a crafted KCM SOCK_SEQPACKET send. After MAX_SKB_FRAGS fills, kcm_sendmsg() links a new skb before copying user data and leaves that zero-fragment tail linked when the copy fails. Completing the saved partial message with a zero-length write makes kcm_write_msgs() hit WARN_ON; a system crash requires warning-to-panic behavior.

The record

CVE
CVE-2026-43244
Published
May 6, 2026
Updated
May 6, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-401, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 6, 2026CVE publishedPublication date reported by the CVE source.
  2. May 6, 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=4.6
  2. Affected versionversion=ab7ac4eb9832e32a09f4e8042705484d2fb0aad3 <7af58f76e4b404a74c836881a845e6652db8a09f
  3. Affected versionversion=ab7ac4eb9832e32a09f4e8042705484d2fb0aad3 <9ea3671d70ee07480d80bebe86696397c4e99fb7
  4. Affected versionversion=ab7ac4eb9832e32a09f4e8042705484d2fb0aad3 <b1e3edf688a88c1a3ac41657055d9c136a08cd25
  5. Affected versionversion=ab7ac4eb9832e32a09f4e8042705484d2fb0aad3 <ca220141fa8ebae09765a242076b2b77338106b0

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=4.6; version=ab7ac4eb9832e32a09f4e8042705484d2fb0aad3 <7af58f76e4b404a74c836881a845e6652db8a09f; version=ab7ac4eb9832e32a09f4e8042705484d2fb0aad3 <9ea3671d70ee07480d80bebe86696397c4e99fb7; version=ab7ac4eb9832e32a09f4e8042705484d2fb0aad3 <b1e3edf688a88c1a3ac41657055d9c136a08cd25; version=ab7ac4eb9832e32a09f4e8042705484d2fb0aad3 <ca220141fa8ebae09765a242076b2b77338106b0

Published CVSS scores

5.5NIST NVDCVSS: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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-401Missing Release of Memory after Effective Lifetime
T1499.004Application or System Exploitation

Public exploit references

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

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