Detections
Analytics

Mozilla Thunderbird < 153.5.1

medium Nessus Plugin ID 369496

Synopsis

A mail client installed on the remote Windows host is affected by multiple vulnerabilities.

Description

The version of Thunderbird installed on the remote Windows host is prior to 153.5.1. It is, therefore, affected by multiple vulnerabilities as referenced in the mfsa2026-115 advisory.

 - Mozilla blocked compromised intermediate eMudhra certificates via OneCRL on the 17th of October which was distributed to clients via RemoteSettings the same day. This update contains the updated OneCRL block list, ensuring clients will block the compromised certificates even if RemoteSettings is disabled by policy or otherwise unavailable in the user's network environment. (CVE-2026-113470)

 - When setting up an account, Thunderbird's Exchange AutoDiscover lookup also queried the domain's AutoDiscover service over plain HTTP. Due to a bug, that unencrypted request included the credentials the user had entered, allowing a network attacker to obtain the user's password. (CVE-2026-113866)

 - Thunderbird did not escape attribute values when serializing outgoing XMPP stanzas. Because values from incoming requests were echoed back in automatic replies, a remote XMPP user could send a crafted request that caused Thunderbird to inject arbitrary stanzas into the user's connection, which the server would then process as if sent by the user. This could be used to send messages or change contact and subscription settings on behalf of the user, without any interaction. This bug only affects Thunderbird's chat feature with XMPP accounts. (CVE-2026-113867)

 - When authenticating to a POP3 or SMTP server using NTLM, Thunderbird did not check whether the server's challenge was valid base64. A malicious server could send a challenge that caused Thunderbird to include uninitialized heap memory in its NTLM response, disclosing that memory to the server. A challenge consisting only of base64 padding also caused an out-of-bounds read, crashing Thunderbird. This affected accounts configured to use NTLM or GSSAPI authentication. The uninitialized memory disclosure only affected NTLM. (CVE-2026-113868)

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

Solution

Upgrade to Mozilla Thunderbird version 153.5.1 or later.

See Also

https://www.mozilla.org/en-US/security/advisories/mfsa2026-115/

Plugin Details

Severity: Medium

ID: 369496

File Name: mozilla_thunderbird_153_5_1.nasl

Version: 1.1

Type: Local

Agent: windows

Family: Windows

Published: 10/21/2026

Updated: 10/21/2026

Supported Sensors: Frictionless Assessment AWS, Frictionless Assessment Azure, Frictionless Assessment Agent, Nessus Agent, Tenable Cloud Security, Tenable Self-Hosted Container Security, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 4.9

Percentile: 58.48

CVSS v2

Risk Factor: Medium

Base Score: 6.4

Temporal Score: 4.7

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

CVSS Score Source: CVE-2026-113470

CVSS v3

Risk Factor: Medium

Base Score: 5.9

Temporal Score: 5.2

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

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

CVSS Score Source: CVE-2026-113866

Vulnerability Information

CPE: cpe:/a:mozilla:thunderbird

Required KB Items: installed_sw/Mozilla Thunderbird

Exploit Ease: No known exploits are available

Patch Publication Date: 10/20/2026

Vulnerability Publication Date: 10/15/2026

Reference Information

CVE: CVE-2026-113470, CVE-2026-113866, CVE-2026-113867, CVE-2026-113868