Out-of-bounds Read in Opensc
CVE-2025-66037
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.
Vulnerability class: Buffer Overflow
EPSS: 0.003 (16.8th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 3.9 (Low). Vector: CVSS:3.1/AV:P/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L.
Affected products
- Opensc — versions < 0.27.0
- Opensc_project Opensc
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Exploit, Vendor Advisory)
- security-advisories@github.com (x_refsource_MISC, Vendor Advisory)
Frequently asked questions
- What is CVE-2025-66037?
- CVE-2025-66037 is a low-severity vulnerability in Opensc, classified under Out-of-bounds Read. CVSS score: 3.9/10. Published 2026-03-30.
- How severe is CVE-2025-66037?
- Low severity. CVSS v3 base score is 3.9 out of 10.