CVE-2025-66037

OpenSC: Out of Bounds vulnerability

MEDIUM
6.8
CVSS Score
Published: March 30, 2026 at 05:01 PM UTC
Updated: June 17, 2026 at 09:56 AM UTC
1 product affected across 1 vendorOpenSC

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Severity
MEDIUM6.8
Exploit prediction
EPSS 0.3%
SSVC
PoC

Description

OpenSC is an open source smart card tools and middleware. Prior to version 0.27.0, feeding a crafted input to the fuzz_pkcs15_reader harness causes OpenSC to perform an out-of-bounds heap read in the X.509/SPKI handling path. Specifically, sc_pkcs15_pubkey_from_spki_fields() allocates a zero-length buffer and then reads one byte past the end of that allocation. This issue has been patched in version 0.27.0.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 0.27.0
Affected range stops below 0.27.0, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (2)

x_refsource_CONFIRMExploitVendor Advisory
Source: cverecord
https://github.com/OpenSC/OpenSC/security/advisories/GHSA-m58q-rmjm-mmfx
x_refsource_MISCVendor Advisory
Source: cverecord
https://github.com/OpenSC/OpenSC/wiki/CVE-2025-66037

SSVC — Action Prioritization

SSVCPoCNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
PHYSICAL
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
CWE-125

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