Detections
Analytics

Ruby net-imap < 0.3.10 / 0.4.x < 0.4.24 / 0.5.x < 0.5.14 / 0.6.x < 0.6.4 vulnerability

high Nessus Plugin ID 313279

Synopsis

The remote host has an application installed that is affected by a man-in-the-middle vulnerability.

Description

The version of the net-imap Ruby library installed on the remote host is prior to 0.3.10, 0.4.x prior to 0.4.24, 0.5.x prior to 0.5.14, or 0.6.x prior to 0.6.4. It is, therefore, affected by a man-in-the-middle vulnerability.

A flaw in the Net::IMAP#starttls function allows a man-in-the-middle attacker to bypass the upgrade to an encrypted TLS connection. By injecting a specially crafted response, the attacker can cause the library to proceed as if the command succeeded without actually establishing TLS encryption. This results in the socket remaining unencrypted, allowing for the interception of cleartext communications unless the client specifically verifies the encryption status.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

Solution

Upgrade to net-imap version 0.3.10, 0.4.24, 0.5.14, or 0.6.4.

See Also

https://github.com/advisories/GHSA-vcgp-9326-pqcp

Plugin Details

Severity: High

ID: 313279

File Name: ruby_gem_netimap_CVE_2026_42246.nasl

Version: 1.1

Type: Local

Agent: windows, macosx, unix

Family: Misc.

Published: 5/8/2026

Updated: 5/8/2026

Configuration: Enable thorough checks (optional)

Supported Sensors: Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: Low

Score: 3.7

CVSS v2

Risk Factor: Medium

Base Score: 5

Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:N/A:N

CVSS Score Source: CVE-2026-42246

CVSS v3

Risk Factor: High

Base Score: 7.5

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

CVSS v4

Risk Factor: High

Base Score: 7.6

Threat Score: 4.9

Threat Vector: CVSS:4.0/E:U

Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N

Vulnerability Information

CPE: cpe:/a:ruby:net-imap

Required KB Items: Host/ruby/modules/enumerated

Patch Publication Date: 4/23/2026

Vulnerability Publication Date: 4/23/2026

Reference Information

CVE: CVE-2026-42246

IAVB: 2026-B-0117