Out-of-bounds Write Affecting wolfSSL/wolfssh package, versions [,5.9.2)
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-UNMANAGED-WOLFSSLWOLFSSH-17660713
- published28 Jun 2026
- disclosed25 Jun 2026
- creditUnknown
Introduced: 25 Jun 2026
CVE-2026-55958 (opens in a new tab)How to fix?
Upgrade wolfSSL/wolfssh to version 5.9.2 or higher.
Overview
Affected versions of this package are vulnerable to Out-of-bounds Write due to improper capacity check in the tsip_StoreMessage function. An attacker can corrupt adjacent heap memory and potentially cause a remote crash by sending an unusually large but valid certificate chain or by acting as a malicious or man-in-the-middle server that sends an oversized handshake message to a client that does not strictly verify the certificate chain. This is only exploitable if the build uses the Renesas TSIP TLS port (WOLFSSL_RENESAS_TSIP_TLS) as a TLS 1.3 client on Renesas MCUs with TSIP hardware enabled.