Bug 2467024 (CVE-2026-43089)

Summary:	CVE-2026-43089 kernel: xfrm_user: fix info leak in build_mapping()
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security <prodsec-ir-bot>
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
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Fixed In Version:		Doc Type:	---
Doc Text:	A flaw was found in the Linux kernel's `xfrm_user` module. A one-byte padding hole in the `struct xfrm_usersa_id` was not properly initialized before being copied to userspace. This information disclosure vulnerability could allow a local attacker to obtain sensitive information from kernel memory.	Story Points:	---
Clone Of:		Environment:
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Regression:	---	Mount Type:	---
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oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2026-05-06 10:03:42 UTC

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

xfrm_user: fix info leak in build_mapping()

struct xfrm_usersa_id has a one-byte padding hole after the proto
field, which ends up never getting set to zero before copying out to
userspace.  Fix that up by zeroing out the whole structure before
setting individual variables.

Comment 1 Alexander B 2026-05-06 13:07:14 UTC

Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026050617-CVE-2026-43089-877c@gregkh/T