CVE-2026-74966

Analyzed Analyzed - Analysis Complete

Information Disclosure in Firefox Form Autofill

Publication date: 2026-08-18

Last updated on: 2026-08-25

Assigner: Mozilla Corporation

Description

Information disclosure in the Form Autofill component. This vulnerability was fixed in Firefox 154, Firefox ESR 153.1, Thunderbird 154, and Thunderbird 153.1.

CVSS Scores

EPSS Scores

Probability:
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Meta Information

Published

2026-08-18

Last Modified

2026-08-25

Generated

2026-09-07

AI Q&A

2026-08-18

EPSS Evaluated

2026-09-06

NVD

CVE-2026-74966

EUVD

EUVD-2026-60686

Affected Vendors & Products

Vendor	Product	Version / Range
mozilla	firefox	to 153.1.0 (exc)
mozilla	thunderbird	to 153.1.0 (exc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-359	The product does not properly prevent a person's private, personal information from being accessed by actors who either (1) are not explicitly authorized to access the information or (2) do not have the implicit consent of the person about whom the information is collected.

Attack-Flow Graph

Executive Summary

This vulnerability is an information disclosure issue in Firefox's Form Autofill component. It was patched in Firefox 154 and Firefox ESR 153.1. The flaw allowed sensitive data to be exposed unintentionally through the autofill feature.

Detection Guidance

This vulnerability is specific to Firefox versions before 154 and Firefox ESR before 153.1. Check your Firefox version via Help > About Firefox in the application or run `firefox --version` in the terminal. If your version is below 154 (or 153.1 for ESR), the system is vulnerable.

Impact Analysis

If exploited, this vulnerability could allow attackers to access personal or sensitive information stored in autofill fields, such as addresses, credit card details, or login credentials. Users of affected Firefox versions are at risk until they update.

Compliance Impact

This vulnerability could lead to non-compliance with GDPR or HIPAA if it results in unauthorized access to protected personal data. Organizations using vulnerable Firefox versions may face legal penalties or data breach notifications.

Mitigation Strategies

Update Firefox to version 154 or later and Firefox ESR to version 153.1 or later. Disable the Form Autofill feature in Firefox settings if an update is not immediately possible. Restart the browser after making changes.

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