# CVE-2026-10275: OpenSC pkcs11-tool Key Generation pkcs11-tool.c test_kpgen_certwrite buffer overflow

CVE-2026-10275 is fixed in 3 products on 1 platform, first by ALAS2023-2026-1898, released June 22, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-10275
- Priority: Routine
- CVSS: 5.0 (Low)
- EPSS: 0.0030
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Jun 1, 2026
- Weakness: Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-10275

## Description

A flaw has been found in OpenSC up to 0.26.1. This affects the function test_kpgen_certwrite of the file src/tools/pkcs11-tool.c of the component pkcs11-tool Key Generation Module. This manipulation causes buffer overflow. The attack is possible to be carried out remotely. The complexity of an attack is rather high. It is indicated that the exploitability is difficult. The exploit has been published and may be used. Patch name: 814f745b3b6d100295f65f1935edd33d520d33ab. It is recommended to apply a patch to fix this issue.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | opensc Debian 14 | 0.27.1-2 | [DEBIAN-CVE-2026-10275](https://patchblox.com/security/data/fix/linux/debian-cve-2026-10275.md) | Jun 24, 2026 |
| Linux | opensc amzn 2023 | 0.24.0-1.amzn2023.0.5 | [ALAS2023-2026-1898](https://patchblox.com/security/data/fix/linux/alas2023-2026-1898.md) | Jun 22, 2026 |
| Linux | opensc opensuse-leap 16.0 | 0.26.1-160000.5.1 | [OPENSUSE-SU-2026:21873-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21873-1.md) | Sep 17, 2026 |
| Linux | opensc sles 15.6 | 0.22.0-150600.11.11.1 | [SUSE-SU-2026:2697-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-2697-1.md) | Jun 30, 2026 |
| Linux | opensc sles 15.7 | 0.22.0-150600.11.11.1 | [SUSE-SU-2026:2697-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-2697-1.md) | Jun 30, 2026 |
| Linux | opensc-debuginfo amzn 2023 | 0.24.0-1.amzn2023.0.5 | [ALAS2023-2026-1898](https://patchblox.com/security/data/fix/linux/alas2023-2026-1898.md) | Jun 22, 2026 |
| Linux | opensc-debugsource amzn 2023 | 0.24.0-1.amzn2023.0.5 | [ALAS2023-2026-1898](https://patchblox.com/security/data/fix/linux/alas2023-2026-1898.md) | Jun 22, 2026 |

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Data as of 2026-11-09T07:25:28Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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