Buffer overflow in Opensc
CVE-2025-66215
OpenSC is an open source smart card tools and middleware. Prior to version 0.27.0, an attacker with physical access to the computer at the time user or administrator uses a token can cause a stack-buffer-overflow WRITE in card-oberthur. The attack requires crafted USB device or smart card that would present the system with specially crafted responses to the APDUs. This issue has been patched in version 0.27.0.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 3.8 (Low). Vector: CVSS:3.1/AV:P/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:L.
EPSS exploit prediction
EPSS: 0.002 (4.3th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 4th percentile — 4.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: 0.000
Affected products
- Opensc — versions < 0.27.0
- Opensc Project
Weakness classification (CWE)
References
- github.com/OpenSC/OpenSC/security/advisories/GHSA-q5fc-cw56-hwp2 (Patch, Vendor Advisory)
- github.com/OpenSC/OpenSC/pull/3436 (Patch, Issue Tracking)
- github.com/OpenSC/OpenSC/commit/efd1d479832141bcf705c2f47655ada4d5f92f5d (Patch)
- github.com/OpenSC/OpenSC/wiki/CVE-2025-66215 (Vendor Advisory)
Frequently asked questions
- What is CVE-2025-66215?
- CVE-2025-66215 is a low-severity vulnerability in Opensc, classified under Stack-based Buffer Overflow. CVSS score: 3.8/10. Published 2026-03-30.
- How severe is CVE-2025-66215?
- Low severity. CVSS v3 base score is 3.8 out of 10.