Data disclosure or crashes via uninitialized APDU buffers
Published Apr 23, 2026 · Updated Apr 23, 2026
Use of uninitialized memory in libopensc before 0.27.0 allows physically proximate attackers to disclose data or crash applications. Several card-detection paths trust short or inconsistent APDU lengths: esteid_select_file parses unfilled bytes as FCI, while cac_read_binary exposes a full-length object with uninitialized regions. Exploitation requires physical connection of a crafted USB device or smart card; the grounded consequences are data disclosure and application crashes.
Summary
What happened
Use of uninitialized memory in libopensc before 0.27.0 allows physically proximate attackers to disclose data or crash applications. Several card-detection paths trust short or inconsistent APDU lengths: esteid_select_file parses unfilled bytes as FCI, while cac_read_binary exposes a full-length object with uninitialized regions. Exploitation requires physical connection of a crafted USB device or smart card; the grounded consequences are data disclosure and application crashes.
The record
- CVE
- CVE-2025-13763
- Published
- Apr 23, 2026
- Updated
- Apr 23, 2026
- Vendor
- OpenSC Project
- Product
- OpenSC
- Classifications
- CWE-457, T1200
- Attack vector
- physical
- Privileges
- unauthenticated
Timeline
How it unfolded
- Apr 23, 2026CVE publishedPublication date reported by the CVE source.
- Apr 23, 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 <0.27.0
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
- fuzz_pkcs15init test-case archiveproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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