CVE-2021-41581

Name: CVE-2021-41581
Creator: NVD / NIST
Published: 2021-09-24T03:15:06.567+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 5.5/10EPSS 0.63%

Last modified Jun 17, 2026

CVE-2021-41581 is a medium-severity vulnerability rated 5.5/10 on the CVSS scale. x509_constraints_parse_mailbox in lib/libcrypto/x509/x509_constraints.c in LibreSSL through 3.4.0 has a stack-based buffer over-read. When the input exceeds DOMAIN_PART_MAX_LEN, the buffer lacks '\0' termination.. EPSS estimates a 0.63% chance of exploitation in the next 30 days.

Description

x509_constraints_parse_mailbox in lib/libcrypto/x509/x509_constraints.c in LibreSSL through 3.4.0 has a stack-based buffer over-read. When the input exceeds DOMAIN_PART_MAX_LEN, the buffer lacks '\0' termination.

Metrics

CVSS 3.1

5.5/10

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

EPSS Probability

0.63%

45.4th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-125

Affected Software

Vendor	Product	Versions
Openbsd	Libressl	<= 3.4.0

References

https://github.com/libressl-portable/openbsd/issues/126Exploit, Issue Tracking, Patch, Third Party Advisory
https://github.com/libressl-portable/openbsd/issues/126Exploit, Issue Tracking, Patch, Third Party Advisory

Timeline

Published: Sep 24, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-41581?

How severe is CVE-2021-41581?

CVE-2021-41581 has a CVSS score of 5.5/10 (MEDIUM severity). The EPSS model estimates a 0.63% probability of exploitation in the next 30 days.

How do I fix CVE-2021-41581?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-41581?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST