CVE-2026-74988: Vulnerability in Mozilla Firefox
Internally found bugs present in Thunderbird ESR 153.0 and Thunderbird 153. Some of these bugs showed evidence of memory corruption or another security-relevant defect and we presume that with enough effort some of these could have been exploited. This vulnerability was fixed in Firefox 154, Firefox ESR 153.1, Thunderbird 154, and Thunderbird 153.1.
AI Analysis
Technical Summary
CVE-2026-74988 covers a set of internally discovered security bugs affecting Mozilla Firefox 153 and Thunderbird 153. These bugs include memory corruption and other critical security defects that could potentially be exploited. The vulnerabilities span multiple components such as Graphics (CanvasWebGL, Text, ImageLib), JavaScript engine (WebAssembly, GC), DOM (Networking, Navigation), and others. The Mozilla Foundation released fixes in Firefox 154, Firefox ESR 153.1, Thunderbird 154, and Thunderbird 153.1. The CVSS v3.1 score is 9.8 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H), reflecting remote exploitability without privileges or user interaction and high impact on confidentiality, integrity, and availability. The vendor advisory confirms the availability of official fixes and no active exploitation is currently known.
Potential Impact
The vulnerabilities have critical impact, allowing remote attackers to potentially execute arbitrary code, escalate privileges, cause information disclosure, or denial of service. The high CVSS score reflects the severity of these issues. Exploitation could compromise user security and privacy. However, no known exploits in the wild have been reported at this time.
Mitigation Recommendations
Official fixes are available and have been released by Mozilla in Firefox 154, Firefox ESR 153.1, Thunderbird 154, and Thunderbird 153.1. Users and administrators should update to these versions immediately to remediate the vulnerabilities. No additional mitigation is required beyond applying the official patches.
CVE-2026-74988: Vulnerability in Mozilla Firefox
Description
Internally found bugs present in Thunderbird ESR 153.0 and Thunderbird 153. Some of these bugs showed evidence of memory corruption or another security-relevant defect and we presume that with enough effort some of these could have been exploited. This vulnerability was fixed in Firefox 154, Firefox ESR 153.1, Thunderbird 154, and Thunderbird 153.1.
CVSS v3.1
Score 9.8critical
Affected software
Mozilla
Firefox
Mozilla
Thunderbird
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-74988 covers a set of internally discovered security bugs affecting Mozilla Firefox 153 and Thunderbird 153. These bugs include memory corruption and other critical security defects that could potentially be exploited. The vulnerabilities span multiple components such as Graphics (CanvasWebGL, Text, ImageLib), JavaScript engine (WebAssembly, GC), DOM (Networking, Navigation), and others. The Mozilla Foundation released fixes in Firefox 154, Firefox ESR 153.1, Thunderbird 154, and Thunderbird 153.1. The CVSS v3.1 score is 9.8 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H), reflecting remote exploitability without privileges or user interaction and high impact on confidentiality, integrity, and availability. The vendor advisory confirms the availability of official fixes and no active exploitation is currently known.
Potential Impact
The vulnerabilities have critical impact, allowing remote attackers to potentially execute arbitrary code, escalate privileges, cause information disclosure, or denial of service. The high CVSS score reflects the severity of these issues. Exploitation could compromise user security and privacy. However, no known exploits in the wild have been reported at this time.
Mitigation Recommendations
Official fixes are available and have been released by Mozilla in Firefox 154, Firefox ESR 153.1, Thunderbird 154, and Thunderbird 153.1. Users and administrators should update to these versions immediately to remediate the vulnerabilities. No additional mitigation is required beyond applying the official patches.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- mozilla
- Date Reserved
- 2026-08-17T11:59:23.074Z
- State
- PUBLISHED
- Vendor Advisory Urls
- [{"url":"https://www.mozilla.org/security/advisories/mfsa2026-74/","vendor":"Mozilla"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-77/","vendor":"Mozilla"}]
Threat ID: 6a84550fc6e8be0332367766
Added to database: 08/18/2026, 12:50:23 UTC
Last enriched: 09/07/2026, 14:15:24 UTC
Last updated: 10/02/2026, 02:46:06 UTC
Views: 96
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