AZL-106353

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Import Source
https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-106353.json
JSON Data
https://api.osv.dev/v1/vulns/AZL-106353
Upstream
Published
2026-10-06T09:18:14Z
Modified
2026-10-07T14:17:01Z
Summary
CVE-2026-98255 affecting package kernel 6.6.157.1-1
Details

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

tcp: exclude old ACKs from tcp fast path

Exclude old ACKs before SND.UNA from the tcp fast path as well as ACKs after SND.NXT.

Such ACKs will fall through to the slow path, where tcp_ack() performs the appropriate validation and challenge ACK handling according to RFC5961 and Commit 3d501dd326fb1c7 ("tcp: do not accept ACK of bytes we never sent").

This prevents old ACKs from being accepted or modifying connection state as part of the fast path before appropriate ACK validation is applied. In particular, this prevents payload carried by a segment with an excessively old ACK from advancing RCV.NXT before the ACK is rejected.

References

Affected packages

Azure Linux:3 / kernel

Package

Name
kernel
Purl
pkg:rpm/azure-linux/kernel

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Last Affected
6.6.157.1-1

Database specific

source
"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-106353.json"