What is CVE-2026-55958?

CVE-2026-55958 is a high-severity vulnerability in Wolfssl, classified under CWE-393. CVSS score: 7.5/10. Published 2026-06-25.

How severe is CVE-2026-55958?

High severity. CVSS v3 base score is 7.5 out of 10.

Buffer overflow in Wolfssl

CVE-2026-55958

Out-of-bounds write in the Renesas TSIP TLS 1.3 transcript buffer. In tsip_StoreMessage() the capacity check guarding the fixed message bag (MSGBAG_SIZE) sets an error code but fails to return, so execution falls through to an XMEMCPY that…

EPSS: 0.004 (33.8th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Affected products

Wolfssl — versions 5.4.0

Weakness classification (CWE)

CWE-393
CWE-787 — Out-of-bounds Write

References

facts@wolfssl.com (Patch, patch, Issue Tracking)
facts@wolfssl.com (Vendor Advisory)

Frequently asked questions

What is CVE-2026-55958?: CVE-2026-55958 is a high-severity vulnerability in Wolfssl, classified under CWE-393. CVSS score: 7.5/10. Published 2026-06-25.
How severe is CVE-2026-55958?: High severity. CVSS v3 base score is 7.5 out of 10.