CVE-2026-89555Network attack vectorHinoki check available

Kernel memory read via stale MPLS header pointer

Published Sep 11, 2026 · Updated Sep 11, 2026

Use-after-free in Linux MPLS multipath routing allows remote attackers to trigger an invalid kernel memory read with a crafted packet. mpls_multipath_hash retains a label-header pointer across pskb_may_pull, which can replace and free the skb head before IPv4 or IPv6 header access. Reachability requires MPLS forwarding, multiple nexthops, and a Geneve packet whose inner header occupies nonlinear data with insufficient linear-head tailroom.

CVSS severityUnavailable
Unscored
EPSS probability0.68%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Use-after-free in Linux MPLS multipath routing allows remote attackers to trigger an invalid kernel memory read with a crafted packet. mpls_multipath_hash retains a label-header pointer across pskb_may_pull, which can replace and free the skb head before IPv4 or IPv6 header access. Reachability requires MPLS forwarding, multiple nexthops, and a Geneve packet whose inner header occupies nonlinear data with insufficient linear-head tailroom.

The record

CVE
CVE-2026-89555
Published
Sep 11, 2026
Updated
Sep 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 11, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 11, 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=4.10
  2. Affected versionversion=4.9.8 <4.10
  3. Affected versionversion=9f427a0e474a67b454420c131709600d44850486 <29e63b8d9fc150cc191b1c6eb7e16e1247e1b650
  4. Affected versionversion=9f427a0e474a67b454420c131709600d44850486 <49d38c1b4390412f8950d33dfaee0ccbd17beb81
  5. Affected versionversion=9f427a0e474a67b454420c131709600d44850486 <d82b90a38c2ca8a0694428eab0e9551c23f2447d
  6. Affected versionversion=9f427a0e474a67b454420c131709600d44850486 <fed638a248116b8a249bd4202d28e5934bdc65ad
  7. Affected versionversion=ad864d9fce0ec56cc8f6afe5c6a0e6d7f484b9eb

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=4.10; version=4.9.8 <4.10; version=9f427a0e474a67b454420c131709600d44850486 <29e63b8d9fc150cc191b1c6eb7e16e1247e1b650; version=9f427a0e474a67b454420c131709600d44850486 <49d38c1b4390412f8950d33dfaee0ccbd17beb81; version=9f427a0e474a67b454420c131709600d44850486 <d82b90a38c2ca8a0694428eab0e9551c23f2447d; version=9f427a0e474a67b454420c131709600d44850486 <fed638a248116b8a249bd4202d28e5934bdc65ad; version=ad864d9fce0ec56cc8f6afe5c6a0e6d7f484b9eb

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)
Vectornetwork
Privilegesunauthenticated
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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