CVE-2026-92239

Analyzed Analyzed - Analysis Complete

Buffer Overflow in Thunderbird via Malicious IMAP Input

Publication date: 2026-09-15

Last updated on: 2026-09-24

Assigner: Mozilla Corporation

Description

A maliciously constructed IMAP line could cause an out-of-bounds buffer read. This vulnerability was fixed in Thunderbird 156 and Thunderbird 140.16.

CVSS Scores

EPSS Scores

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Meta Information

Published

2026-09-15

Last Modified

2026-09-24

Generated

2026-10-06

AI Q&A

2026-09-16

EPSS Evaluated

2026-10-04

NVD

CVE-2026-92239

EUVD

EUVD-2026-79243

Affected Vendors & Products

Vendor	Product	Version / Range
mozilla	thunderbird	to 140.16.0 (exc)
mozilla	thunderbird	From 141.0 (inc) to 153.3.0 (exc)
mozilla	thunderbird	From 154.0 (inc) to 156.0 (exc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-125	The product reads data past the end, or before the beginning, of the intended buffer.

Attack-Flow Graph

Executive Summary

This vulnerability involves a maliciously crafted IMAP line that triggers an out-of-bounds buffer read in Thunderbird. This occurs when the software attempts to read memory outside the intended buffer due to improper input validation.

Detection Guidance

This vulnerability is specific to Thunderbird versions before 156 and 140.16. Detection involves checking installed Thunderbird versions. Use commands like 'thunderbird --version' or check package managers (e.g., 'dpkg -l | grep thunderbird' on Debian/Ubuntu). If outdated, update immediately.

Impact Analysis

An attacker could exploit this to cause crashes, data corruption, or potentially execute arbitrary code on your system. It may lead to unauthorized access or loss of sensitive information if exploited successfully.

Compliance Impact

The provided CVE data does not specify how this vulnerability impacts compliance with standards like GDPR or HIPAA. The vulnerability involves an out-of-bounds buffer read in IMAP processing, which could lead to information disclosure or crashes, but no direct compliance implications are mentioned.

Mitigation Strategies

Update Thunderbird to version 156 or 140.16 or later to address the out-of-bounds buffer read vulnerability.

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