CVE-2026-42771
openssl: Possible Out of Bounds Read in X509_VERIFY_PARAM_set1_email()
Severity
LowRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · July 10, 2026
Updated · September 21, 2026
Description
A flaw was found in OpenSSL. When an application uses the X509_VERIFY_PARAM_set1_email() function to validate a specially crafted S/MIME (Secure/Multipurpose Internet Mail Extensions) email address, an out-of-bounds read can occur. A remote attacker could exploit this vulnerability by sending a malicious email, leading to an application crash and a Denial of Service (DoS). This issue does not directly expose sensitive data.
Statement
This flaw is rated as Low impact. A possible out-of-bounds read in OpenSSL's X509_VERIFY_PARAM_set1_email() function can occur when an application validates a specially crafted S/MIME email address. This could lead to a denial of service through an application crash, but does not directly exfiltrate data.
CVSS score applicability
The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
CVSS / CWE
CVSS 3.1 · 6.5CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
CWE-805 · Buffer Access with Incorrect Length Value