CVE-2026-89476

sctp: fix stream->outcnt underflow on duplicate RECONF responses

State: Published
Severity: 7.5 High
Published: Sep 11, 2026
Updated: Oct 19, 2026
Reserved: Sep 11, 2026

Description

In the Linux kernel, the following vulnerability has been resolved:

sctp: fix stream->outcnt underflow on duplicate RECONF responses

A cached RECONF chunk may contain more than one request parameter. A duplicate response can therefore find and process the same ADD_OUT request again while another parameter is still outstanding, rolling back outcnt twice and possibly underflowing it.

Track outstanding request types as bits and clear each bit after its first response. Later responses for the same request are then ignored.

Scores

CVSS	Score	Vector	Source
3.1	7.5 High	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H	Linux

Weaknesses

The record names no weakness.

Affected Products

Product	Versions
LinuxLinux	11ae76e67a179f25ae8f772d62a7ddf717b1cdf3 to before 041f7df5a929d3e7435dd8387e8ea17f2d412b7dAffected 11ae76e67a179f25ae8f772d62a7ddf717b1cdf3 to before 59f61c39cb99ee1737bd742a20094fe5653389bbAffected 11ae76e67a179f25ae8f772d62a7ddf717b1cdf3 to before 793519e343867ee9a3e84f6cac07f81f2aec7b5dAffected 11ae76e67a179f25ae8f772d62a7ddf717b1cdf3 to before 092acd3c55a4077b00489064615d8d2d898daf91Affected 11ae76e67a179f25ae8f772d62a7ddf717b1cdf3 to before 2d867663c563e8009257b9edf9c8ec75d9bbf19aAffected 11ae76e67a179f25ae8f772d62a7ddf717b1cdf3 to before d02a5794c3deedcb8476d017fcee2b7aaedab2e1Affected 11ae76e67a179f25ae8f772d62a7ddf717b1cdf3 to before 8320cbd81bc21a1ca6ebdf70ad610ebc5ef1bd68Affected 11ae76e67a179f25ae8f772d62a7ddf717b1cdf3 to before 3faf13aff243ca9f78d08b1a2956ef5a6fc77b6eAffected
LinuxLinux	4.12Affected before 4.12Not affected 5.10.270 through 5.10.Not affected 5.15.221 through 5.15.Not affected 6.1.188 through 6.1.Not affected 6.6.157 through 6.6.Not affected 6.12.109 through 6.12.Not affected 6.18.50 through 6.18.Not affected 7.2.4 through 7.2.*Not affected 7.3 and laterNot affected

Product

Versions

LinuxLinux

11ae76e67a179f25ae8f772d62a7ddf717b1cdf3 to before 041f7df5a929d3e7435dd8387e8ea17f2d412b7dAffected
11ae76e67a179f25ae8f772d62a7ddf717b1cdf3 to before 59f61c39cb99ee1737bd742a20094fe5653389bbAffected
11ae76e67a179f25ae8f772d62a7ddf717b1cdf3 to before 793519e343867ee9a3e84f6cac07f81f2aec7b5dAffected
11ae76e67a179f25ae8f772d62a7ddf717b1cdf3 to before 092acd3c55a4077b00489064615d8d2d898daf91Affected
11ae76e67a179f25ae8f772d62a7ddf717b1cdf3 to before 2d867663c563e8009257b9edf9c8ec75d9bbf19aAffected
11ae76e67a179f25ae8f772d62a7ddf717b1cdf3 to before d02a5794c3deedcb8476d017fcee2b7aaedab2e1Affected
11ae76e67a179f25ae8f772d62a7ddf717b1cdf3 to before 8320cbd81bc21a1ca6ebdf70ad610ebc5ef1bd68Affected
11ae76e67a179f25ae8f772d62a7ddf717b1cdf3 to before 3faf13aff243ca9f78d08b1a2956ef5a6fc77b6eAffected

LinuxLinux

4.12Affected
before 4.12Not affected
5.10.270 through 5.10.*Not affected
5.15.221 through 5.15.*Not affected
6.1.188 through 6.1.*Not affected
6.6.157 through 6.6.*Not affected
6.12.109 through 6.12.*Not affected
6.18.50 through 6.18.*Not affected
7.2.4 through 7.2.*Not affected
7.3 and laterNot affected

References

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