# CVE-2025-66038: opensc: OpenSC is an open source smart card tools and middleware

CVE-2025-66038 is fixed in opensc on 1 platform, first by DEBIAN-CVE-2025-66038, released March 30, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2025-66038
- Priority: Routine
- CVSS: 6.8 (medium)
- EPSS: 0.0029
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Mar 30, 2026

## Description

OpenSC is an open source smart card tools and middleware. Prior to version 0.27.0, sc_compacttlv_find_tag searches a compact-TLV buffer for a given tag. In compact-TLV, a single byte encodes the tag (high nibble) and value length (low nibble). With a 1-byte buffer {0x0A}, the encoded element claims tag=0 and length=10 but no value bytes follow. Calling sc_compacttlv_find_tag with search tag 0x00 returns a pointer equal to buf+1 and outlen=10 without verifying that the claimed value length fits within the remaining buffer. In cases where the sc_compacttlv_find_tag is provided untrusted data (such as being read from cards/files), attackers may be able to influence it to return out-of-bounds pointers leading to downstream memory corruption when subsequent code tries to dereference the pointer. This issue has been patched in version 0.27.0.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | opensc Debian 14 | 0.27.0~rc1-1 | [DEBIAN-CVE-2025-66038](https://patchblox.com/security/data/fix/linux/debian-cve-2025-66038.md) | Mar 30, 2026 |
| Linux | opensc opensuse-leap 16.0 | 0.26.1-160000.3.1 | [OPENSUSE-SU-2026:20967-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-20967-1.md) | Jun 15, 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 sles 16.0 | 0.26.1-160000.3.1 | [SUSE-SU-2026:22126-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-22126-1.md) | Jun 15, 2026 |

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Data as of 2026-11-08T06:59:42Z 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 Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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