CVE-2026-98101Hinoki check available

Multicast packet misdelivery via unsynchronized RCU updates

Published Sep 25, 2026 · Updated Sep 25, 2026

Race condition in Linux IPv6 multicast source filtering allows attackers to cause incorrect UDP and raw packet delivery during concurrent updates. The ip6_mc_source() path mutated RCU-visible source addresses and counts in place, and could publish a replacement list before adding the new address. Concurrent inet6_mc_check() readers could therefore observe torn IPv6 addresses or duplicated or missing entries; exploitation requires a local process to race source-filter changes with packet reception.

CVSS severityUnavailable
Unscored
EPSS probability0.17%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Race condition in Linux IPv6 multicast source filtering allows attackers to cause incorrect UDP and raw packet delivery during concurrent updates. The ip6_mc_source() path mutated RCU-visible source addresses and counts in place, and could publish a replacement list before adding the new address. Concurrent inet6_mc_check() readers could therefore observe torn IPv6 addresses or duplicated or missing entries; exploitation requires a local process to race source-filter changes with packet reception.

The record

CVE
CVE-2026-98101
Published
Sep 25, 2026
Updated
Sep 25, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
Unavailable
Privileges
Unavailable

Timeline

How it unfolded

  1. Sep 25, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 25, 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=47c75e3923c8d562fea8daf0ccf31546a7bef0ea
  2. Affected versionversion=5.10.261 <5.11
  3. Affected versionversion=5.13
  4. Affected versionversion=882ba1f73c06831f2a21044ebd8864c485ac04f2 <20db91a052332ef5552bd2f651ffb9db911cf67b
  5. Affected versionversion=882ba1f73c06831f2a21044ebd8864c485ac04f2 <2c2091e2ee93049fc513ad1e6c99d8b6c809f467
  6. Affected versionversion=882ba1f73c06831f2a21044ebd8864c485ac04f2 <c073d1b070f171d206b19c98d71739a97f15b3f1

What conditions does exploitation require?

Attack vectorUnavailable in this record.
Required privilegesUnavailable in this record.

What is affected?

The Linux Kernel Organization · Linuxversion=47c75e3923c8d562fea8daf0ccf31546a7bef0ea; version=5.10.261 <5.11; version=5.13; version=882ba1f73c06831f2a21044ebd8864c485ac04f2 <20db91a052332ef5552bd2f651ffb9db911cf67b; version=882ba1f73c06831f2a21044ebd8864c485ac04f2 <2c2091e2ee93049fc513ad1e6c99d8b6c809f467; version=882ba1f73c06831f2a21044ebd8864c485ac04f2 <c073d1b070f171d206b19c98d71739a97f15b3f1

Published CVSS scores

No CVSS assessment is available in this record.

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.

Activity data is delayed. The latest report is Sep 28, 2026.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
VectorUnavailable
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

No sourced classifications are available.

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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