CVE-2009-3765

mutt_ssl.c in mutt 1.5.19 and 1.5.20, when OpenSSL is used, does not properly handle a '\0' character in a domain name in the subject's Common Name (CN) field of an X.509 certificate, which allows man-in-the-middle attackers to spoof arbitrary SSL servers via a crafted certificate issued by a legitimate Certification Authority, a related issue to CVE-2009-2408.

Published: 2009-10-23 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2009-3765 is rated Moderate Risk (49/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 1.08%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2009-3765

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.59% 1.08% +0.50%
2 2025-12-28 0.53% 0.59% +0.06%
3 2025-12-27 — 0.53% —

Full EPSS history (14 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2009-3765

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.8 2.0 MEDIUM
AV:N/AC:M/Au:N/C:P/I:P/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
 8.6 6.4 [email protected]

Weakness enumeration for CVE-2009-3765

OS Trackers for CVE-2009-3765

vendor priority summary link
debian unimportant CVE-2009-3765 unimportant priority: Debian including 1 source packages (mutt), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2009-3765
redhat medium — https://access.redhat.com/security/cve/CVE-2009-3765
ubuntu negligible CVE-2009-3765 negligible priority: Ubuntu including 1 source packages (mutt), 7 status rows across 7 suites (dapper, hardy, intrepid, jaunty, karmic, lucid, upstream): ignored 6, needs-triage 1. https://ubuntu.com/security/CVE-2009-3765

Vendor comments (NVD) for CVE-2009-3765

  • Red Hat (2009-10-26T00:00:00)

    Not vulnerable. This issue did not affect the versions of mutt as shipped with Red Hat Enterprise Linux 3, 4, or 5.

Affected software / configurations for CVE-2009-3765

Vendor Product Version Raw CPE
mutt mutt 1.5.19 cpe:2.3:a:mutt:mutt:1.5.19:*:*:*:*:*:*:*
mutt mutt 1.5.20 cpe:2.3:a:mutt:mutt:1.5.20:*:*:*:*:*:*:*

References for CVE-2009-3765

cvelogic Threat Intelligence