CVE-2026-42771
MediumCVSS 6.2Exploitation Probability (EPSS)
Low risk5th percentile - higher than 5% of all known CVEs
Summary
CVE-2026-42771 concerns the X509_VERIFY_PARAM_set1_email function, which may lead to an out of bounds read when validating an email address. This can result in application crashes and denial of service.
Risk Assessment
The risk to the organization involves potential system crashes, leading to service interruptions related to S/MIME message validation.
Recommendation
It is recommended to update the software to the latest version to mitigate this vulnerability and to monitor systems for potential crashes.
Original NVD description (English source)
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 will not directly exfiltrate the data read to the attacker so the most likely result is a crash and a Denial of Service. An internal helper function called from X509_VERIFY_PARAM_[set|add]_email() used a wrong length when validating the local part of an email address. This could cause the 64 octet limit on the local part of an email address to be not enforced, or cause an out of bound read and potentially a crash. The bug is reachable via S-MIME validation with a crafted From: address supplied in an email message that can potentially cause a crash. No FIPS modules are affected by this issue as the affected code is outside the OpenSSL FIPS module boundary.