# CVE-2025-50343: libmatio: An issue was discovered in matio 1.5.28

CVE-2025-50343 is fixed in libmatio on 1 platform, first by DEBIAN-CVE-2025-50343, released December 30, 2025. It is not reported as exploited. Patch Radar priority: Urgent.

- Web page: https://patchblox.com/security/cve/CVE-2025-50343
- Priority: Urgent
- CVSS: 9.8 (critical)
- EPSS: n/a
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Dec 30, 2025

## Description

An issue was discovered in matio 1.5.28. A heap-based memory corruption can occur in Mat_VarCreateStruct() when the nfields value does not match the actual number of strings in the fields array. This leads to out-of-bounds reads and invalid memory frees during cleanup, potentially causing a segmentation fault or heap corruption. NOTE: Multiple third-parties note that the available evidence does not demonstrate a vulnerability exploitable through an attacker-controlled input path.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | libmatio Debian 12.15 (bookworm) | 1.5.23-2+deb12u1 | [DEBIAN-CVE-2025-50343](https://patchblox.com/security/data/fix/linux/debian-cve-2025-50343.md) | Dec 30, 2025 |
| Linux | libmatio Debian 14 | 1.5.30-2 | [DEBIAN-CVE-2025-50343](https://patchblox.com/security/data/fix/linux/debian-cve-2025-50343.md) | Dec 30, 2025 |

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Data as of 2026-11-09T01:18:40Z 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 Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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