CVE-2026-74987: Vulnerability in Mozilla Firefox
Internally found bugs present in Firefox ESR 140.13, Firefox ESR 153.0 and Firefox 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 140.14, and Firefox ESR 153.1.
AI Analysis
Technical Summary
CVE-2026-74987 encompasses a set of internally discovered security bugs affecting Mozilla Firefox ESR 140.13, ESR 153.0, and Firefox 153. These bugs involve memory corruption and other security-relevant defects that could be exploited with sufficient effort. The vulnerabilities cover multiple components including Graphics (CanvasWebGL, Text, ImageLib, Canvas2D), JavaScript engine (WebAssembly, GC, JIT), DOM (Networking, Navigation, Core & HTML, Service Workers), Remote Settings Client, Safe Browsing, Storage (Cache API), WebRTC, and others. Mozilla released fixes in Firefox 154, Firefox ESR 140.14, and Firefox ESR 153.1 to address these issues. No known exploits in the wild have been reported.
Potential Impact
The vulnerabilities have high impact potential, including sandbox escapes, privilege escalation, use-after-free conditions, information disclosure, and mitigation bypasses. These could allow attackers to escalate privileges, bypass security mitigations, or disclose sensitive information if exploited. However, no active exploitation in the wild has been reported to date.
Mitigation Recommendations
Mozilla has released official fixes for these vulnerabilities in Firefox 154, Firefox ESR 140.14, and Firefox ESR 153.1. Users and administrators should update to these versions or later to mitigate the risks. No additional mitigation actions are required beyond applying these updates.
CVE-2026-74987: Vulnerability in Mozilla Firefox
Description
Internally found bugs present in Firefox ESR 140.13, Firefox ESR 153.0 and Firefox 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 140.14, and Firefox ESR 153.1.
Affected software
pkg:github/mozilla/firefoxRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-74987 encompasses a set of internally discovered security bugs affecting Mozilla Firefox ESR 140.13, ESR 153.0, and Firefox 153. These bugs involve memory corruption and other security-relevant defects that could be exploited with sufficient effort. The vulnerabilities cover multiple components including Graphics (CanvasWebGL, Text, ImageLib, Canvas2D), JavaScript engine (WebAssembly, GC, JIT), DOM (Networking, Navigation, Core & HTML, Service Workers), Remote Settings Client, Safe Browsing, Storage (Cache API), WebRTC, and others. Mozilla released fixes in Firefox 154, Firefox ESR 140.14, and Firefox ESR 153.1 to address these issues. No known exploits in the wild have been reported.
Potential Impact
The vulnerabilities have high impact potential, including sandbox escapes, privilege escalation, use-after-free conditions, information disclosure, and mitigation bypasses. These could allow attackers to escalate privileges, bypass security mitigations, or disclose sensitive information if exploited. However, no active exploitation in the wild has been reported to date.
Mitigation Recommendations
Mozilla has released official fixes for these vulnerabilities in Firefox 154, Firefox ESR 140.14, and Firefox ESR 153.1. Users and administrators should update to these versions or later to mitigate the risks. No additional mitigation actions are required beyond applying these updates.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- mozilla
- Date Reserved
- 2026-08-17T11:59:22.495Z
- Cvss Version
- null
- State
- PUBLISHED
- Remediation Level
- null
- Vendor Advisory Urls
- [{"url":"https://www.mozilla.org/security/advisories/mfsa2026-74/","vendor":"Mozilla"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-76/","vendor":"Mozilla"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-77/","vendor":"Mozilla"}]
Threat ID: 6a84550fc6e8be0332367764
Added to database: 08/18/2026, 12:50:23 UTC
Last enriched: 08/18/2026, 13:11:40 UTC
Last updated: 08/18/2026, 13:37:35 UTC
Views: 4
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