CVE-2026-45850

Service interruption via misaligned IPv6 checksum validation

Published May 27, 2026 · Updated May 27, 2026

Improper checksum validation in Linux Kernel IPVS allows local users to interrupt IPv6 load-balanced traffic with extension headers. The TCP, UDP, and SCTP checksum paths start validation at the fixed IPv6 header length instead of the parsed iph->len transport offset, so extension-header bytes are included in the checksum calculation. Reachability requires IPVS to process locally supplied IPv6 traffic containing extension headers; affected packets fail validation, interrupting their load-balanced delivery.

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

What happened

Improper checksum validation in Linux Kernel IPVS allows local users to interrupt IPv6 load-balanced traffic with extension headers. The TCP, UDP, and SCTP checksum paths start validation at the fixed IPv6 header length instead of the parsed iph->len transport offset, so extension-header bytes are included in the checksum calculation. Reachability requires IPVS to process locally supplied IPv6 traffic containing extension headers; affected packets fail validation, interrupting their load-balanced delivery.

The record

CVE
CVE-2026-45850
Published
May 27, 2026
Updated
May 27, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
T1499
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=0bbdd42b7efa66685b6d74701bcde3a596a3a59d <05cfe9863ef049d98141dc2969eefde72fb07625
  2. Affected versionversion=0bbdd42b7efa66685b6d74701bcde3a596a3a59d <a3ca27762ce8476b4fbf9b2a8f5cb74c38e483e4
  3. Affected versionversion=2.6.28

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=0bbdd42b7efa66685b6d74701bcde3a596a3a59d <05cfe9863ef049d98141dc2969eefde72fb07625; version=0bbdd42b7efa66685b6d74701bcde3a596a3a59d <a3ca27762ce8476b4fbf9b2a8f5cb74c38e483e4; version=2.6.28

Published CVSS scores

5.5NVDCVSS: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

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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