Heap overflow via mismatched WMF text lengths
Published Sep 22, 2026 · Updated Sep 22, 2026
Heap buffer overflow in LibreOffice 26.2 before 26.2.5 allows attackers to trigger an out-of-bounds access via a crafted WMF graphic. The WMF text-record importer reads the text length and character-advance count independently, then indexes the shorter advance array by text position. Exploitation requires LibreOffice to import the crafted graphic, including through a document that embeds it; the advisory establishes memory access beyond the heap allocation but does not claim code execution.
Summary
What happened
Heap buffer overflow in LibreOffice 26.2 before 26.2.5 allows attackers to trigger an out-of-bounds access via a crafted WMF graphic. The WMF text-record importer reads the text length and character-advance count independently, then indexes the shorter advance array by text position. Exploitation requires LibreOffice to import the crafted graphic, including through a document that embeds it; the advisory establishes memory access beyond the heap allocation but does not claim code execution.
The record
- CVE
- CVE-2026-63272
- Published
- Sep 22, 2026
- Updated
- Sep 22, 2026
- Vendor
- The Document Foundation
- Product
- LibreOffice
- Classifications
- T1204.002
- Attack vector
- local
- Privileges
- unauthenticated
Timeline
How it unfolded
- Sep 22, 2026CVE publishedPublication date reported by the CVE source.
- Sep 22, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=26.2 << 26.2.5
What conditions does exploitation require?
What is affected?
Published CVSS scores
No CVSS assessment is available in this record.
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Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Activity data is delayed. The latest report is Sep 28, 2026.
Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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