Out-of-bounds write in wolfSSL - CVE-2026-55958
Published: July 1, 2026
Vulnerability identifier: #VU136630
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-55958
CWE-ID: CWE-787
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: wolfSSL
Affected software:
wolfSSL
wolfSSL
Detailed vulnerability description
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to an out-of-bounds write in tsip_StoreMessage() when processing an oversized TLS 1.3 handshake transcript. A remote attacker can send an unusually large but valid certificate chain or oversized handshake message to cause a denial of service.
Only builds using the Renesas TSIP TLS port as a TLS 1.3 client on Renesas MCUs with TSIP hardware enabled are affected.
How to mitigate CVE-2026-55958
Install security update from vendor's website.