Bug 2541208 (CVE-2026-97596)

Summary:	CVE-2026-97596 kernel: ipvs: reject invalid states in connection template sync records
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security DevOps Team <prodsec-dev>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	akhatavk, aos-team-art-private, asdas, dpaolell, jdelft, jupierce, lgarciaa, mbiarnes, ppalepu, ppostler, prdhamdh, rhel-process-autobot, sghai, sidsharm, suppawar, vlaad, watson-tool-maintainers
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	---
Doc Text:	A flaw was found in the Linux kernel's IP Virtual Server (IPVS) subsystem. An attacker capable of sending network synchronization messages can transmit connection template records containing invalid protocol states, which the sync receiver stores rather than rejects. When the system subsequently processes these connections, protocols such as TCP use the invalid state to index internal transition tables, leading to out-of-bounds memory access that can cause a system crash and Denial of Service (DoS).	Story Points:	---
Clone Of:		Environment:
Last Closed:		Type:	---
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Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2026-09-25 11:01:55 UTC

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

ipvs: reject invalid states in connection template sync records

IPVS sync receivers validate protocol states before creating or updating a
connection. For connection templates, however, they only log states outside
the template state range and still store the value in the connection.

A template can be returned by ordinary connection lookup. TCP and SCTP then
use the invalid state as an index into their transition tables.

Reject invalid template states in both sync protocol versions before
looking up or modifying a connection. The version 1 path handles both
IPv4 and IPv6 records.

Comment 1 gkamathe 2026-09-29 11:12:40 UTC

Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-97596.mbox