CVE-2025-66037

Name: CVE-2025-66037
Creator: NVD / NIST
Published: 2026-03-30T18:16:18.007+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.8/10EPSS 0.25%

Last modified Jun 17, 2026

CVE-2025-66037 is a medium-severity vulnerability rated 6.8/10 on the CVSS scale. 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. EPSS estimates a 0.25% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1

6.8/10

CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

0.25%

16.5th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-125

Affected Software

Vendor	Product	Versions
Opensc Project	Opensc	< 0.27.0

References

https://github.com/OpenSC/OpenSC/security/advisories/GHSA-m58q-rmjm-mmfxExploit, Vendor Advisory
https://github.com/OpenSC/OpenSC/wiki/CVE-2025-66037Vendor Advisory

Timeline

Published: Mar 30, 2026
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2025-66037?

How severe is CVE-2025-66037?

CVE-2025-66037 has a CVSS score of 6.8/10 (MEDIUM severity). The EPSS model estimates a 0.25% probability of exploitation in the next 30 days.

How do I fix CVE-2025-66037?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2025-66037?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST