Memory disclosure via unchecked OpenType metric length
Published Mar 11, 2025 · Updated Feb 26, 2026
Out-of-bounds reading in Adobe Acrobat Reader 25.001.20428 and earlier allows attackers to disclose memory through a malicious PDF. The CoolType OpenType parser trusts hhea.numberOfHMetrics when the hmtx table is shorter than four bytes per declared metric, then reads hMetric data past the table boundary. A context-dependent attacker must persuade a victim to open the crafted PDF; the demonstrated consequence is sensitive-memory disclosure that can weaken ASLR.
Summary
What happened
Out-of-bounds reading in Adobe Acrobat Reader 25.001.20428 and earlier allows attackers to disclose memory through a malicious PDF. The CoolType OpenType parser trusts hhea.numberOfHMetrics when the hmtx table is shorter than four bytes per declared metric, then reads hMetric data past the table boundary. A context-dependent attacker must persuade a victim to open the crafted PDF; the demonstrated consequence is sensitive-memory disclosure that can weaken ASLR.
The record
- CVE
- CVE-2025-27163
- Published
- Mar 11, 2025
- Updated
- Feb 26, 2026
- Vendor
- Adobe
- Product
- Adobe Acrobat Reader
- Classifications
- CWE-125, T1203
- Attack vector
- local
- Privileges
- unauthenticated
Timeline
How it unfolded
- Mar 11, 2025CVE publishedPublication date reported by the CVE source.
- Feb 26, 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=0 <=25.001.20428
What conditions does exploitation require?
What is affected?
Published CVSS scores
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.
Public exploit references
- Cisco Talos OpenType hMetric proof of conceptproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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