CVE-2026-72021Network attack vector

Service disruption via misparsed IPv6 SCTP offset

Published Aug 15, 2026 · Updated Aug 15, 2026

Improper SCTP state handling in Linux allows remote attackers to disrupt IPVS service via crafted IPv6 packets with extension headers. The set_sctp_state() function assumes a fixed IPv6-header length instead of using the parsed transport offset, causing it to interpret a verification-tag byte as the SCTP chunk type. Exposure requires an IPVS SCTP virtual service reachable over IPv6; exploitation assigns an incomplete connection a longer timeout and corrupts destination accounting, enabling network-resource exhaustion.

CVSS severity8.2
High
EPSS probability0.59%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper SCTP state handling in Linux allows remote attackers to disrupt IPVS service via crafted IPv6 packets with extension headers. The set_sctp_state() function assumes a fixed IPv6-header length instead of using the parsed transport offset, causing it to interpret a verification-tag byte as the SCTP chunk type. Exposure requires an IPVS SCTP virtual service reachable over IPv6; exploitation assigns an incomplete connection a longer timeout and corrupts destination accounting, enabling network-resource exhaustion.

The record

CVE
CVE-2026-72021
Published
Aug 15, 2026
Updated
Aug 15, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-125, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 15, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 15, 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=2.6.34
  2. Affected versionversion=2906f66a5682e5670a5eefe991843689b8d8563f <247d055504dcc852e539b9f7f30d19f9741474bf
  3. Affected versionversion=2906f66a5682e5670a5eefe991843689b8d8563f <290e9e8389b556efc603522e28bd1543846aa336
  4. Affected versionversion=2906f66a5682e5670a5eefe991843689b8d8563f <2f75c0faa3361b28e36cc0512b3299e163e25789
  5. Affected versionversion=2906f66a5682e5670a5eefe991843689b8d8563f <9cb5ac594ca76d3a71803b23b74c835b0721e628
  6. Affected versionversion=2906f66a5682e5670a5eefe991843689b8d8563f <9f94573ab962a9e81954b755da016fa3cd2f5039
  7. Affected versionversion=2906f66a5682e5670a5eefe991843689b8d8563f <a4a2d2e483d79cc2ad3a170674cf159644acf22b
  8. Affected versionversion=2906f66a5682e5670a5eefe991843689b8d8563f <d2b8b1557ec07ea1bb5dddbceaf4dfe63d388e27
  9. Affected versionversion=2906f66a5682e5670a5eefe991843689b8d8563f <e5d0bb8871668f20de8f3c94b5ae3f372346bc6e

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=2.6.34; version=2906f66a5682e5670a5eefe991843689b8d8563f <247d055504dcc852e539b9f7f30d19f9741474bf; version=2906f66a5682e5670a5eefe991843689b8d8563f <290e9e8389b556efc603522e28bd1543846aa336; version=2906f66a5682e5670a5eefe991843689b8d8563f <2f75c0faa3361b28e36cc0512b3299e163e25789; version=2906f66a5682e5670a5eefe991843689b8d8563f <9cb5ac594ca76d3a71803b23b74c835b0721e628; version=2906f66a5682e5670a5eefe991843689b8d8563f <9f94573ab962a9e81954b755da016fa3cd2f5039; version=2906f66a5682e5670a5eefe991843689b8d8563f <a4a2d2e483d79cc2ad3a170674cf159644acf22b; version=2906f66a5682e5670a5eefe991843689b8d8563f <d2b8b1557ec07ea1bb5dddbceaf4dfe63d388e27; version=2906f66a5682e5670a5eefe991843689b8d8563f <e5d0bb8871668f20de8f3c94b5ae3f372346bc6e

Published CVSS scores

8.2Linux kernel CVE teamCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H

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

CWE-125Out-of-bounds Read
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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