CVE-2025-66038 — Buffer Over-read in Opensc

CWE-126 — Buffer Over-readCWE-805 — Buffer Access with Incorrect Length Value7 documents7 sources
Severity
6.8MEDIUMNVD
CNA3.9
EPSS
0.0%
top 94.43%
CISA KEV
Not in KEV
Exploit
No known exploits
Affected products
2
OpenscOpensc Project Opensc
Timeline
PublishedMar 30

Description

OpenSC is an open source smart card tools and middleware. Prior to version 0.27.0, sc_compacttlv_find_tag searches a compact-TLV buffer for a given tag. In compact-TLV, a single byte encodes the tag (high nibble) and value length (low nibble). With a 1-byte buffer {0x0A}, the encoded element claims tag=0 and length=10 but no value bytes follow. Calling sc_compacttlv_find_tag with search tag 0x00 returns a pointer equal to buf+1 and outlen=10 without verifying that the claimed value length fits w…

CVSS vector

CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HExploitability: 0.9 | Impact: 5.9

Affected Packages3 packages

▶CVEListV5opensc/opensc< 0.27.0
▶NVDopensc_project/opensc< 0.27.0
▶Debianopensc_project/opensc< 0.27.0~rc1-1

Patches

Patch: github.com ↗

🔴Vulnerability Details

2
OSV
CVE-2025-66038: OpenSC is an open source smart card tools and middleware↗2026-03-30
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CVEList
OpenSC: `sc_compacttlv_find_tag` can return out-of-bounds pointers↗2026-03-30
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📋Vendor Advisories

2
Red Hat
OpenSC: OpenSC: Memory corruption via improper compact-TLV length validation↗2026-03-30
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Debian
CVE-2025-66038: opensc - OpenSC is an open source smart card tools and middleware. Prior to version 0.27....↗2025
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🕵️Threat Intelligence

1
Wiz
CVE-2025-66038 Impact, Exploitability, and Mitigation Steps | Wiz↗
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💬Community

1
Bugzilla
CVE-2025-66038 opensc: OpenSC: Memory corruption via improper compact-TLV length validation [fedora-all]↗2026-03-30
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CVE-2025-66038 — Buffer Over-read in Opensc | cvebase