# CVE-2022-35409: mbedtls: An issue was discovered in Mbed TLS before 2.28.1 and 3.x before 3.2.0

CVE-2022-35409 is fixed in mbedtls on 1 platform, first by DEBIAN-CVE-2022-35409, released July 15, 2022. It is not reported as exploited. Patch Radar priority: Urgent.

- Web page: https://patchblox.com/security/cve/CVE-2022-35409
- Priority: Urgent
- CVSS: 9.1 (critical)
- EPSS: 0.0230
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Jul 15, 2022

## Description

An issue was discovered in Mbed TLS before 2.28.1 and 3.x before 3.2.0. In some configurations, an unauthenticated attacker can send an invalid ClientHello message to a DTLS server that causes a heap-based buffer over-read of up to 255 bytes. This can cause a server crash or possibly information disclosure based on error responses. Affected configurations have MBEDTLS_SSL_DTLS_CLIENT_PORT_REUSE enabled and MBEDTLS_SSL_IN_CONTENT_LEN less than a threshold that depends on the configuration: 258 bytes if using mbedtls_ssl_cookie_check, and possibly up to 571 bytes with a custom cookie check function.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | mbedtls Debian 12.15 (bookworm) | 2.28.1-1 | [DEBIAN-CVE-2022-35409](https://patchblox.com/security/data/fix/linux/debian-cve-2022-35409.md) | Jul 15, 2022 |
| Linux | mbedtls Debian 13.5 (trixie) | 2.28.1-1 | [DEBIAN-CVE-2022-35409](https://patchblox.com/security/data/fix/linux/debian-cve-2022-35409.md) | Jul 15, 2022 |
| Linux | mbedtls Debian 14 | 2.28.1-1 | [DEBIAN-CVE-2022-35409](https://patchblox.com/security/data/fix/linux/debian-cve-2022-35409.md) | Jul 15, 2022 |

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Data as of 2026-11-08T00:53:09Z 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 Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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