Bug 2488959 (CVE-2026-8358)

Summary:	CVE-2026-8358 LibreOffice: LibreOffice Calc: Heap buffer overflow leads to denial of service via crafted spreadsheet document.
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 heap-based buffer overflow vulnerability was discovered in LibreOffice Calc's spreadsheet importer. When processing tracked changes from a spreadsheet document, the application fails to properly handle duplicate change identifiers. By reusing the same change identifier for two distinct types of change objects, a maliciously crafted document can trick the importer into treating a change object as a different, larger data type than originally allocated. This mismatch causes the importer to write data past the boundaries of the allocated heap buffer, which could result in a denial of service (application crash) or limited impacts to confidentiality and integrity under the privileges of the current user.	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:
Bug Depends On:	2491389
Bug Blocks:

Description OSIDB Bzimport 2026-06-15 18:01:29 UTC

LibreOffice Calc can import tracked changes from a spreadsheet document. A heap buffer overflow existed when a document reused the same change identifier for two different kinds of change. The importer then treated one change object as a different, larger type and wrote past the end of its allocation. In fixed versions records with a duplicate identifier are rejected.