Memory corruption via oversized PDF decryption key
Published Sep 22, 2026 · Updated Sep 22, 2026
Heap buffer overflow in LibreOffice 26.2 before 26.2.5 allows attackers to corrupt memory by importing a crafted encrypted PDF. The PDF importer trusts the encryption dictionary's key length and uses it to fill a fixed-size heap buffer without checking its capacity. Importing the crafted PDF is required; the documented consequence is an out-of-bounds heap write, with no published code-execution claim.
Summary
What happened
Heap buffer overflow in LibreOffice 26.2 before 26.2.5 allows attackers to corrupt memory by importing a crafted encrypted PDF. The PDF importer trusts the encryption dictionary's key length and uses it to fill a fixed-size heap buffer without checking its capacity. Importing the crafted PDF is required; the documented consequence is an out-of-bounds heap write, with no published code-execution claim.
The record
- CVE
- CVE-2026-63273
- 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.
CVSS describes severity. EPSS estimates exploitation probability.
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
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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