What is CVE-2026-6291?

CVE-2026-6291 is a medium-severity vulnerability in Wolfssl, classified under CWE-208. CVSS score: 6.5/10. Published 2026-06-25.

How severe is CVE-2026-6291?

Medium severity. CVSS v3 base score is 6.5 out of 10.

Vulnerability in Wolfssl

CVE-2026-6291

Bleichenbacher padding oracle in PKCS#7 KTRI decryption. When decrypting PKCS#7 EnvelopedData using RSA PKCS#1 v1.5 key transport, wolfSSL returned distinguishable error codes depending on whether RSA padding validation failed versus wheth…

EPSS: 0.002 (4.9th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N.

Affected products

Wolfssl — versions 3.9.10

Weakness classification (CWE)

CWE-208

References

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

Frequently asked questions

What is CVE-2026-6291?: CVE-2026-6291 is a medium-severity vulnerability in Wolfssl, classified under CWE-208. CVSS score: 6.5/10. Published 2026-06-25.
How severe is CVE-2026-6291?: Medium severity. CVSS v3 base score is 6.5 out of 10.