CVE-2026-40510: OpenSC < 0.27.0-rc1 Stack Buffer Overflow via piv_process_history() in card-piv.c

Severity: medium (CVSS 6.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-05-29 · updated 2026-07-21
Weakness: CWE-121

Description

OpenSC before 0.27.0-rc1, fixed in commit 3f24f0b, contains a stack buffer overflow vulnerability in piv_process_history() in src/libopensc/card-piv.c that allows physically present attackers to trigger memory corruption by presenting a crafted PIV smart card or USB device returning a URL field longer than 118 bytes in the Key History Object ASN.1 response.

Affected products

OpenSC: before 0.27.0 — fixed in 0.27.0

How to fix

Upgrade to a fixed version: OpenSC 0.27.0. Check the vendor advisory for mitigations.

References

https://github.com/OpenSC/OpenSC/commit/3f24f0b48a481a8cf2e46059d8238a283ddc1c13
https://github.com/OpenSC/OpenSC/pull/3558
https://www.vulncheck.com/advisories/opensc-stack-buffer-overflow-via-piv-process-history-in-card-piv-c

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