Bug 2516380 (CVE-2026-68477)

Summary:	CVE-2026-68477 kernel: ipvs: fix more places with wrong ipv6 transport offsets
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:	rhel-process-autobot, 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) component. This vulnerability arises from incorrect IPv6 transport offsets, where TCP application code might incorrectly assume an IPv4 network header when processing IPv6 packets. Additionally, the ICMPv6 header offset in ip_vs_out_icmp_v6() could be incorrect when IPv6 packets contain extension headers. These issues can lead to problems with applications over IPv6 and affect checksum calculations, potentially causing packet processing errors.	Story Points:	---
Clone Of:		Environment:
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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 2026-08-15 06:09:28 UTC

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

ipvs: fix more places with wrong ipv6 transport offsets

Sashiko reports for more incorrect IPv6 transport offsets.

The app code for TCP was assuming IPv4 network header
even after the ipvsh argument was provided. This can
cause problems with apps over IPv6. As for the only
official app in the kernel tree (FTP) this problem is
harmless because we use Netfilter to mangle the FTP
ports and we do not adjust the TCP seq numbers.

Also, provide correct offset of the ICMPV6 header in
ip_vs_out_icmp_v6() for correct checksum checks when
the IPv6 packet has extension headers.

Comment 1 Keith Grant 2026-08-17 14:45:17 UTC

Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026081506-CVE-2026-68477-c9aa@gregkh/T