CVE-2026-98794Network attack vectorHinoki check available

Connection-state disruption via unchecked synchronization flags

Published Oct 18, 2026 · Updated Oct 18, 2026

Improper flag validation in Linux IPVS allows remote attackers to disrupt backup connection handling via crafted synchronization messages. The receive handlers in ip_vs_sync.c accept NO_CPORT combined with TEMPLATE, allowing normal connection lookups to match templates, and version 0 accepts ONE_PACKET records that create unhashed, immediately discarded connections. Exploitation requires access to an enabled backup synchronization receiver; upstream does not specify a resulting crash or hang.

CVSS severityUnavailable
Unscored
EPSS probability0.20%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Improper flag validation in Linux IPVS allows remote attackers to disrupt backup connection handling via crafted synchronization messages. The receive handlers in ip_vs_sync.c accept NO_CPORT combined with TEMPLATE, allowing normal connection lookups to match templates, and version 0 accepts ONE_PACKET records that create unhashed, immediately discarded connections. Exploitation requires access to an enabled backup synchronization receiver; upstream does not specify a resulting crash or hang.

The record

CVE
CVE-2026-98794
Published
Oct 18, 2026
Updated
Oct 18, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Oct 18, 2026CVE publishedPublication date reported by the CVE source.
  2. Oct 18, 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=2.6.14
  2. Affected versionversion=87375ab47cd0ba04124c6d3fd80db5c368f5dcb6 <45a93111835ccfea7d969ec73588e33745fd9834
  3. Affected versionversion=87375ab47cd0ba04124c6d3fd80db5c368f5dcb6 <55d033324f67a15ff56be6d38d6e87f644e0ed62
  4. Affected versionversion=87375ab47cd0ba04124c6d3fd80db5c368f5dcb6 <f4cd1db7d421e82945713a36084bb0c35b75b27e
  5. Affected versionversion=87375ab47cd0ba04124c6d3fd80db5c368f5dcb6 <f96e91748f6304668fe647e686d199d7207d36f1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=2.6.14; version=87375ab47cd0ba04124c6d3fd80db5c368f5dcb6 <45a93111835ccfea7d969ec73588e33745fd9834; version=87375ab47cd0ba04124c6d3fd80db5c368f5dcb6 <55d033324f67a15ff56be6d38d6e87f644e0ed62; version=87375ab47cd0ba04124c6d3fd80db5c368f5dcb6 <f4cd1db7d421e82945713a36084bb0c35b75b27e; version=87375ab47cd0ba04124c6d3fd80db5c368f5dcb6 <f96e91748f6304668fe647e686d199d7207d36f1

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)
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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