CVE-2026-93304 Affecting wolfssl package, versions *


Severity

Recommended
low

Based on default assessment until relevant scores are available.

Threat Intelligence

EPSS
0.19% (9th percentile)

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  • Snyk IDSNYK-DEBIANUNSTABLE-WOLFSSL-20186131
  • published28 Sept 2026
  • disclosed27 Sept 2026

Introduced: 27 Sep 2026

NewCVE-2026-93304  (opens in a new tab)

How to fix?

There is no fixed version for Debian:unstable wolfssl.

NVD Description

Note: Versions mentioned in the description apply only to the upstream wolfssl package and not the wolfssl package as distributed by Debian. See How to fix? for Debian:unstable relevant fixed versions and status.

A (D)TLS 1.2 client can accept a ChangeCipherSpec message before it has sent its ClientKeyExchange. No master secret has been derived at that point, so the client installs read keys derived from a known (deterministic) key and checks the server's Finished against that same key. An out-of-order ChangeCipherSpec can therefore be used by an attacker to complete the handshake in place of the server and send data the client accepts as authentic. The client's own traffic still uses correctly derived keys, so the attacker cannot read it, and the genuine server never completes the handshake. DTLS 1.2 clients are exposed because a datagram read can deliver the out-of-order records on its own. TLS 1.2 clients are exposed when the application supplies received bytes with wolfSSL_inject() or enables read ahead. For certificate suites, the attacker must be in a man-in-the-middle position. For PSK (Pre Shared Key) connections, any fake server can succeed without knowing the PSK.