CVE-2026-74978
Clickjacking issue in the Widget component
Description
Clickjacking issue in the Widget component. This vulnerability was fixed in Firefox 154, Firefox ESR 153.1, Thunderbird 154, and Thunderbird 153.1.
INFO
Published Date :
Aug. 18, 2026, 1:17 p.m.
Last Modified :
Aug. 25, 2026, 4:09 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | HIGH | 134c704f-9b21-4f2e-91b3-4a467353bcc0 |
Solution
- Update the Widget component to Firefox 154 or later.
- Update the Widget component to Firefox ESR 153.1 or later.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-74978.
| URL | Resource |
|---|---|
| https://bugzilla.mozilla.org/show_bug.cgi?id=2036097 | Permissions Required |
| https://www.mozilla.org/security/advisories/mfsa2026-74/ | Vendor Advisory |
| https://www.mozilla.org/security/advisories/mfsa2026-77/ | Vendor Advisory |
| https://www.mozilla.org/security/advisories/mfsa2026-78/ | Vendor Advisory |
| https://www.mozilla.org/security/advisories/mfsa2026-80/ | Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-74978 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-74978
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-74978 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-74978 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Aug. 25, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:* versions up to (excluding) 153.1.0 *cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:* versions up to (excluding) 153.1.0 Added Reference Type Mozilla Corporation: https://bugzilla.mozilla.org/show_bug.cgi?id=2036097 Types: Permissions Required Added Reference Type Mozilla Corporation: https://www.mozilla.org/security/advisories/mfsa2026-74/ Types: Vendor Advisory Added Reference Type Mozilla Corporation: https://www.mozilla.org/security/advisories/mfsa2026-77/ Types: Vendor Advisory Added Reference Type Mozilla Corporation: https://www.mozilla.org/security/advisories/mfsa2026-78/ Types: Vendor Advisory Added Reference Type Mozilla Corporation: https://www.mozilla.org/security/advisories/mfsa2026-80/ Types: Vendor Advisory -
CVE Modified by [email protected]
Aug. 18, 2026
Action Type Old Value New Value Changed Affected [{'vendor': 'Mozilla', 'product': 'Firefox', 'versions': [{'status': 'unaffected', 'version': '153.1', 'versionType': 'rpm', 'lessThanOrEqual': '153.*'}, {'status': 'unaffected', 'version': '154', 'versionType': 'rpm', 'lessThanOrEqual': '*'}]}] [{'vendor': 'Mozilla', 'product': 'Firefox', 'versions': [{'status': 'unaffected', 'version': '153.1', 'versionType': 'rpm', 'lessThanOrEqual': '153.*'}, {'status': 'unaffected', 'version': '154', 'versionType': 'rpm', 'lessThanOrEqual': '*'}]}, {'vendor': 'Mozilla', 'product': 'Thunderbird', 'versions': [{'status': 'unaffected', 'version': '153.1', 'versionType': 'rpm', 'lessThanOrEqual': '153.*'}, {'status': 'unaffected', 'version': '154', 'versionType': 'rpm', 'lessThanOrEqual': '*'}]}] Changed Description Clickjacking issue in the Widget component. This vulnerability was fixed in Firefox 154 and Firefox ESR 153.1. Clickjacking issue in the Widget component. This vulnerability was fixed in Firefox 154, Firefox ESR 153.1, Thunderbird 154, and Thunderbird 153.1. Added Reference https://www.mozilla.org/security/advisories/mfsa2026-78/ Added Reference https://www.mozilla.org/security/advisories/mfsa2026-80/ -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Aug. 18, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N Added CWE CWE-1021 Added SSVC {'id': 'CVE-2026-74978', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-08-18T18:57:54.498666Z'} -
New CVE Received by [email protected]
Aug. 18, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'Mozilla', 'product': 'Firefox', 'versions': [{'status': 'unaffected', 'version': '153.1', 'versionType': 'rpm', 'lessThanOrEqual': '153.*'}, {'status': 'unaffected', 'version': '154', 'versionType': 'rpm', 'lessThanOrEqual': '*'}]}] Added Description Clickjacking issue in the Widget component. This vulnerability was fixed in Firefox 154 and Firefox ESR 153.1. Added Reference https://bugzilla.mozilla.org/show_bug.cgi?id=2036097 Added Reference https://www.mozilla.org/security/advisories/mfsa2026-74/ Added Reference https://www.mozilla.org/security/advisories/mfsa2026-77/