CVE-2026-6766

Received Received - Intake

Boundary Error in NSS Libraries Causes Potential Security Risk

Publication date: 2026-04-21

Last updated on: 2026-04-22

Assigner: Mozilla Corporation

Description

Incorrect boundary conditions in the Libraries component in NSS. This vulnerability was fixed in Firefox 150, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.

CVSS Scores

EPSS Scores

Probability:
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Meta Information

Published

2026-04-21

Last Modified

2026-04-22

Generated

2026-07-06

AI Q&A

2026-04-21

EPSS Evaluated

2026-07-05

NVD

CVE-2026-6766

EUVD

EUVD-2026-24107

Affected Vendors & Products

Vendor	Product	Version / Range
mozilla	firefox	to 150.0 (exc)
mozilla	firefox	to 140.10.0 (exc)
mozilla	thunderbird	to 140.10.0 (exc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-754	The product does not check or incorrectly checks for unusual or exceptional conditions that are not expected to occur frequently during day to day operation of the product.

Attack-Flow Graph

Executive Summary

This vulnerability involves incorrect boundary conditions in the Libraries component of NSS (Network Security Services). It means that certain checks or limits within the code were not properly enforced, potentially leading to unexpected behavior or security issues.

The issue was addressed and fixed in Firefox version 150 and Firefox ESR 140.10.

Impact Analysis

This vulnerability involves incorrect boundary conditions in the Libraries component of NSS, which could potentially lead to security issues in affected versions of Mozilla Firefox and Firefox ESR before the fixes were applied.

It was fixed in Firefox 150 and Firefox ESR 140.10, so using versions prior to these may expose you to risks related to this vulnerability.

Mitigation Strategies

The vulnerability was fixed in Firefox 150 and Firefox ESR 140.10. To mitigate this vulnerability, you should update your Firefox or Firefox ESR browsers to at least these versions.

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