What is CVE-2026-42771?

CVE-2026-42771 is a medium-severity vulnerability in Openssl, classified under Out-of-bounds Read. CVSS score: 6.2/10. Published 2026-06-09.

How severe is CVE-2026-42771?

Medium severity. CVSS v3 base score is 6.2 out of 10.

Out-of-bounds Read in Openssl

CVE-2026-42771

Issue summary: When the X509_VERIFY_PARAM_set1_email is called by an application to validate a crafted e-mail address, such as during S/MIME message validation, an out of bounds read can happen. Impact summary: This out of bounds read wil…

Vulnerability class: Buffer Overflow

EPSS: 0.002 (12.4th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.2 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Affected products

Openssl — versions 4.0.0

Weakness classification (CWE)

CWE-125 — Out-of-bounds Read

References

openssl-security@openssl.org
openssl-security@openssl.org (vendor-advisory, Vendor Advisory)
openssl-security@openssl.org (Patch, patch)

Frequently asked questions

What is CVE-2026-42771?: CVE-2026-42771 is a medium-severity vulnerability in Openssl, classified under Out-of-bounds Read. CVSS score: 6.2/10. Published 2026-06-09.
How severe is CVE-2026-42771?: Medium severity. CVSS v3 base score is 6.2 out of 10.