Kernel crash via duplicate SCTP RECONF responses
Published Sep 11, 2026 · Updated Sep 11, 2026
Integer underflow in affected Linux kernel SCTP builds allows remote attackers to crash the kernel through duplicate RECONF responses. The sctp_process_strreset_resp() path reprocesses a denied ADD_OUT_STREAMS request while another request remains outstanding, subtracts the requested stream count twice, and leaves an inflated 16-bit outcnt that permits a later NULL-slot dereference. Exploitation requires remote attackers to control an SCTP peer on an association where the local application requests both incoming and outgoing streams; a later send to the falsely valid stream ID triggers the crash.
Summary
What happened
Integer underflow in affected Linux kernel SCTP builds allows remote attackers to crash the kernel through duplicate RECONF responses. The sctp_process_strreset_resp() path reprocesses a denied ADD_OUT_STREAMS request while another request remains outstanding, subtracts the requested stream count twice, and leaves an inflated 16-bit outcnt that permits a later NULL-slot dereference. Exploitation requires remote attackers to control an SCTP peer on an association where the local application requests both incoming and outgoing streams; a later send to the falsely valid stream ID triggers the crash.
The record
- CVE
- CVE-2026-89476
- Published
- Sep 11, 2026
- Updated
- Sep 11, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- T1499.004
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Sep 11, 2026CVE publishedPublication date reported by the CVE source.
- 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.
- Affected versionversion=11ae76e67a179f25ae8f772d62a7ddf717b1cdf3 <2d867663c563e8009257b9edf9c8ec75d9bbf19a
- Affected versionversion=11ae76e67a179f25ae8f772d62a7ddf717b1cdf3 <3faf13aff243ca9f78d08b1a2956ef5a6fc77b6e
- Affected versionversion=11ae76e67a179f25ae8f772d62a7ddf717b1cdf3 <8320cbd81bc21a1ca6ebdf70ad610ebc5ef1bd68
- Affected versionversion=11ae76e67a179f25ae8f772d62a7ddf717b1cdf3 <d02a5794c3deedcb8476d017fcee2b7aaedab2e1
- Affected versionversion=4.12
What conditions does exploitation require?
What is affected?
Published CVSS scores
No CVSS assessment is available in this record.
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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.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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