CVE-2026-42771CWE-125

Possible Out of Bounds Read in X509_VERIFY_PARAM_set1_email()

Medium · published June 9, 2026

CVSS v3.1
6.2
EPSS
0%
Percentile
4.9
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
6.2 · MEDIUM
Vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS v4.0
Not supplied
EPSS
0.00160 · 4.9th percentile
Weakness
CWE-125 · Out-of-bounds Read
Published
2026-06-09T16:03Z
EPSS history
Timeline
  • 09 JUN 16:03Z
    Possible Out of Bounds Read in X509_VERIFY_PARAM_set1_email()
    cvelistv5