Bug 2461762 (CVE-2026-31679)

Summary:	CVE-2026-31679 kernel: openvswitch: validate MPLS set/set_masked payload length
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 openvswitch component. This vulnerability arises from improper validation of Multiprotocol Label Switching (MPLS) payload lengths during SET/SET_MASKED actions. An attacker could potentially exploit this by providing malformed MPLS key data, leading to unexpected behavior or a denial of service (DoS) condition within the kernel.	Story Points:	---
Clone Of:		Environment:
Last Closed:		Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2026-04-25 09:01:52 UTC

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

openvswitch: validate MPLS set/set_masked payload length

validate_set() accepted OVS_KEY_ATTR_MPLS as variable-sized payload for
SET/SET_MASKED actions. In action handling, OVS expects fixed-size
MPLS key data (struct ovs_key_mpls).

Use the already normalized key_len (masked case included) and reject
non-matching MPLS action key sizes.

Reject invalid MPLS action payload lengths early.

Comment 1 Alexander B 2026-04-27 10:32:11 UTC

Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026042544-CVE-2026-31679-7f32@gregkh/T