CVE-2026-89950Hinoki check available

Kernel crash via nonlinear multicast socket buffer

Published Sep 16, 2026 · Updated Sep 16, 2026

A packet-handling flaw in Linux 6.8 allows attackers to crash the kernel through batman-adv multicast packet generation. The batadv_mcast_forw_mcsend path unshares but does not linearize a nonlinear socket buffer before batadv_mcast_forw_scrape or batadv_mcast_forw_packet invokes SKB_LINEAR_ASSERT, triggering BUG(). Reaching the fault requires multicast packet generation through an active batman-adv mesh interface; the reported consequence is a fatal kernel BUG and service interruption.

CVSS severityUnavailable
Unscored
EPSS probabilityUnavailable
No score available in this record
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

A packet-handling flaw in Linux 6.8 allows attackers to crash the kernel through batman-adv multicast packet generation. The batadv_mcast_forw_mcsend path unshares but does not linearize a nonlinear socket buffer before batadv_mcast_forw_scrape or batadv_mcast_forw_packet invokes SKB_LINEAR_ASSERT, triggering BUG(). Reaching the fault requires multicast packet generation through an active batman-adv mesh interface; the reported consequence is a fatal kernel BUG and service interruption.

The record

CVE
CVE-2026-89950
Published
Sep 16, 2026
Updated
Sep 16, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
Attack vector
Unavailable
Privileges
Unavailable

Timeline

How it unfolded

  1. Sep 16, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 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=6.8
  2. Affected versionversion=90039133221e33964ccb4a536dad7eb0a372fff7 <2879177539e3ece483a8e5406970373698e9a6c5
  3. Affected versionversion=90039133221e33964ccb4a536dad7eb0a372fff7 <6a30a59e2660afd03c975f1b8eae6a2301161197
  4. Affected versionversion=90039133221e33964ccb4a536dad7eb0a372fff7 <a9603e0a7cb5e0cddc6b23af153cf7daafc5c55e
  5. Affected versionversion=90039133221e33964ccb4a536dad7eb0a372fff7 <c32e5e25c41201c8c3b796a4ab2c45103187091e

What conditions does exploitation require?

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

What is affected?

The Linux Kernel Organization · Linuxversion=6.8; version=90039133221e33964ccb4a536dad7eb0a372fff7 <2879177539e3ece483a8e5406970373698e9a6c5; version=90039133221e33964ccb4a536dad7eb0a372fff7 <6a30a59e2660afd03c975f1b8eae6a2301161197; version=90039133221e33964ccb4a536dad7eb0a372fff7 <a9603e0a7cb5e0cddc6b23af153cf7daafc5c55e; version=90039133221e33964ccb4a536dad7eb0a372fff7 <c32e5e25c41201c8c3b796a4ab2c45103187091e

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.

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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)
VectorUnavailable
PrivilegesUnavailable
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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