CVE-2026-6753

Modified Modified - Updated After Analysis

Boundary Condition Error in Firefox WebRTC Causes Potential Exploit

Publication date: 2026-04-21

Last updated on: 2026-06-30

Assigner: Mozilla Corporation

Description

Incorrect boundary conditions in the WebRTC component. 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

2026-06-30

Generated

2026-07-06

AI Q&A

2026-04-22

EPSS Evaluated

2026-07-05

NVD

CVE-2026-6753

EUVD

EUVD-2026-24094

Affected Vendors & Products

Vendor	Product	Version / Range
mozilla	firefox	to 150.0 (exc)
mozilla	firefox	to 140.10.0 (exc)
mozilla	thunderbird	From 140.0 (inc) to 140.10.0 (exc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-119	The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.
CWE-787	The product writes data past the end, or before the beginning, of the intended buffer.

Attack-Flow Graph

Impact Analysis

This vulnerability involves incorrect boundary conditions in the WebRTC component, which could potentially lead to unexpected behavior or security issues when using affected versions of Firefox or Thunderbird.

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

Executive Summary

This vulnerability involves incorrect boundary conditions in the WebRTC component of Mozilla Firefox. It means that the software did not properly handle certain limits or edges in the WebRTC code, which could potentially lead to unexpected behavior or security issues. The problem was addressed and fixed in Firefox version 150 and Firefox ESR 140.10.

Mitigation Strategies

To mitigate this vulnerability, update your Firefox browser to version 150 or later, or Firefox ESR to version 140.10 or later, where the issue has been fixed.

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