CVE-2006-2659

libs/comverp.c in Courier MTA before 0.53.2 allows attackers to cause a denial of service (CPU consumption) via unknown vectors involving usernames that contain the "=" (equals) character, which is not properly handled during encoding.

Published: 2006-05-30 Last update: 2026-04-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2006-2659 is rated Moderate Risk (62.4/100): CVSS High severity, with medium exploitation likelihood (EPSS 3.56%). 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-2006-2659

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 2025-06-23 2.86% 3.56% +0.70%
2 2025-03-30 2.66% 2.86% +0.21%
3 2025-03-29 — 2.66% —

Full EPSS history (11 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2006-2659

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.8 2.0 HIGH
AV:N/AC:L/Au:N/C:N/I:N/A:C Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:C)
Complete availability impact.
 10.0 6.9 [email protected]

Weakness enumeration for CVE-2006-2659

OS Trackers for CVE-2006-2659

vendor priority summary link
debian not yet assigned CVE-2006-2659 not yet assigned priority: Debian including 1 source packages (courier), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2006-2659
gentoo normal CVE-2006-2659: 1 GLSA(s) (200608-06), 1 atom(s) (mail-mta/courier); latest impact normal. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2006-2659
ubuntu medium CVE-2006-2659 medium priority: Ubuntu including 1 source packages (courier), 4 status rows across 4 suites (dapper, edgy, feisty, upstream): released 3, needs-triage 1. https://ubuntu.com/security/CVE-2006-2659

NVD evaluator notes for CVE-2006-2659

Solution: This vulnerability is addressed in the following product release: Double Precision Incorporated, Courier MTA, 0.53.2

Affected software / configurations for CVE-2006-2659

Vendor Product Version Raw CPE
double_precision_incorporated courier_mta <= 0.44.2 cpe:2.3:a:double_precision_incorporated:courier_mta:*:*:*:*:*:*:*:*
double_precision_incorporated courier_mta 0.37.3 cpe:2.3:a:double_precision_incorporated:courier_mta:0.37.3:*:*:*:*:*:*:*
double_precision_incorporated courier_mta 0.38.1 cpe:2.3:a:double_precision_incorporated:courier_mta:0.38.1:*:*:*:*:*:*:*
double_precision_incorporated courier_mta 0.40 cpe:2.3:a:double_precision_incorporated:courier_mta:0.40:*:*:*:*:*:*:*
double_precision_incorporated courier_mta 0.43 cpe:2.3:a:double_precision_incorporated:courier_mta:0.43:*:*:*:*:*:*:*
double_precision_incorporated courier_mta 0.43.1 cpe:2.3:a:double_precision_incorporated:courier_mta:0.43.1:*:*:*:*:*:*:*
double_precision_incorporated courier_mta 0.43.2 cpe:2.3:a:double_precision_incorporated:courier_mta:0.43.2:*:*:*:*:*:*:*
double_precision_incorporated courier_mta 0.44 cpe:2.3:a:double_precision_incorporated:courier_mta:0.44:*:*:*:*:*:*:*

References for CVE-2006-2659

cvelogic Threat Intelligence