CVE-2026-89968Network attack vector

Unauthenticated service hang via unsolicited H2CData

Published Sep 16, 2026 · Updated Sep 16, 2026

Denial of service in affected Linux kernels allows remote attackers to hang nvmet-tcp via an unsolicited H2CData PDU. nvmet_tcp_handle_h2c_data_pdu() accepts data before sending R2T, allowing one command to complete twice and self-link its response-list node. An allow_any_host subsystem permits unauthenticated triggering, causing a kernel BUG with CONFIG_DEBUG_LIST or an nvmet-tcp workqueue soft lockup otherwise.

CVSS severityUnavailable
Unscored
EPSS probabilityUnavailable
No score available in this record
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

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Summary

What happened

Denial of service in affected Linux kernels allows remote attackers to hang nvmet-tcp via an unsolicited H2CData PDU. nvmet_tcp_handle_h2c_data_pdu() accepts data before sending R2T, allowing one command to complete twice and self-link its response-list node. An allow_any_host subsystem permits unauthenticated triggering, causing a kernel BUG with CONFIG_DEBUG_LIST or an nvmet-tcp workqueue soft lockup otherwise.

The record

CVE
CVE-2026-89968
Published
Sep 16, 2026
Updated
Sep 16, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499.004
Attack vector
network
Privileges
unauthenticated

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=5.0
  2. Affected versionversion=872d26a391da92ed8f0c0f5cb5fef428067b7f30 <02341ee424fb2eed16b5b8a9d247492e49335c21
  3. Affected versionversion=872d26a391da92ed8f0c0f5cb5fef428067b7f30 <14beef7d4f123fb458fc9844aa74a071871dcca6
  4. Affected versionversion=872d26a391da92ed8f0c0f5cb5fef428067b7f30 <1cbed7538946c99e585acefd11c9ba3a0bdbae05
  5. Affected versionversion=872d26a391da92ed8f0c0f5cb5fef428067b7f30 <2b71f9193e3d3a352920ba367f1a6db345249038
  6. Affected versionversion=872d26a391da92ed8f0c0f5cb5fef428067b7f30 <9fb527103e53fd43a8e802c2eca407869c204f7a
  7. Affected versionversion=872d26a391da92ed8f0c0f5cb5fef428067b7f30 <cade124c06f8e738e3a0df285ed2e08953e6bfaa
  8. Affected versionversion=872d26a391da92ed8f0c0f5cb5fef428067b7f30 <cf1484d9a75de6809ef331e16f525aaa41b0e16d
  9. Affected versionversion=872d26a391da92ed8f0c0f5cb5fef428067b7f30 <db62b35cbca052860c519cbcabe7650708528738

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.0; version=872d26a391da92ed8f0c0f5cb5fef428067b7f30 <02341ee424fb2eed16b5b8a9d247492e49335c21; version=872d26a391da92ed8f0c0f5cb5fef428067b7f30 <14beef7d4f123fb458fc9844aa74a071871dcca6; version=872d26a391da92ed8f0c0f5cb5fef428067b7f30 <1cbed7538946c99e585acefd11c9ba3a0bdbae05; version=872d26a391da92ed8f0c0f5cb5fef428067b7f30 <2b71f9193e3d3a352920ba367f1a6db345249038; version=872d26a391da92ed8f0c0f5cb5fef428067b7f30 <9fb527103e53fd43a8e802c2eca407869c204f7a; version=872d26a391da92ed8f0c0f5cb5fef428067b7f30 <cade124c06f8e738e3a0df285ed2e08953e6bfaa; version=872d26a391da92ed8f0c0f5cb5fef428067b7f30 <cf1484d9a75de6809ef331e16f525aaa41b0e16d; version=872d26a391da92ed8f0c0f5cb5fef428067b7f30 <db62b35cbca052860c519cbcabe7650708528738

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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499.004Application or System Exploitation

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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