CVE-2026-100757
HIGHCVSS 8.8/10EPSS 0.34%
Last modified
CVE-2026-100757 is a high-severity vulnerability rated 8.8/10 on the CVSS scale. Use-after-free in the Widget component. This vulnerability was fixed in Firefox ESR 153.4, Thunderbird 157, Thunderbird 140.17, Thunderbird 153.4, Firefox 157, Firefox ESR 115.42, and Firefox ESR 140.17.. EPSS estimates a 0.34% chance of exploitation in the next 30 days.
Description
Use-after-free in the Widget component. This vulnerability was fixed in Firefox ESR 153.4, Thunderbird 157, Thunderbird 140.17, Thunderbird 153.4, Firefox 157, Firefox ESR 115.42, and Firefox ESR 140.17.
Metrics
Weakness Enumeration
Affected Software
| Vendor | Product | Versions |
|---|---|---|
| Mozilla | Firefox | < 115.42.0 |
| Mozilla | Firefox | >= 116.0.0, < 140.17.0 |
| Mozilla | Firefox | >= 141.0.0, < 153.4.0 |
| Mozilla | Firefox | >= 154.0.0, < 157.0.0 |
| Mozilla | Thunderbird | < 140.17.0 |
| Mozilla | Thunderbird | >= 141.0, < 153.4.0 |
| Mozilla | Thunderbird | >= 154.0, < 157.0 |
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=2049352Permissions Required
- https://www.mozilla.org/security/advisories/mfsa2026-100/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2026-101/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2026-102/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2026-103/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2026-97/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2026-98/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2026-99/Vendor Advisory
Timeline
- Published
- Last Modified
- Status
- Analyzed
Frequently Asked Questions
What is CVE-2026-100757?
Use-after-free in the Widget component. This vulnerability was fixed in Firefox ESR 153.4, Thunderbird 157, Thunderbird 140.17, Thunderbird 153.4, Firefox 157, Firefox ESR 115.42, and Firefox ESR 140.17.
How severe is CVE-2026-100757?
CVE-2026-100757 has a CVSS score of 8.8/10 (HIGH severity). The EPSS model estimates a 0.34% probability of exploitation in the next 30 days.
How do I fix CVE-2026-100757?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.
How Strix Helps
- How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
- Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
- PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
- AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.
Related CVEs from 2026
- CVE-2026-100750Joomla Extension - regularlabs.com - LFI / SSRF in Modules A…7.5
- CVE-2026-100751Joomla Extension - regularlabs.com - Privileged stored XSS v…6.1
- CVE-2026-100752Joomla Extension - ordasoft.com - Unauthenticated SQL Inject…9.8
- CVE-2026-100753Joomla Extension - ordasoft.com - Reflected Cross-Site Scrip…6.1
- CVE-2026-100755GitLab has remediated an issue in GitLab CE/EE affecting all…4.6
- CVE-2026-100756Incorrect boundary conditions in the Audio/Video: Playback c…8.1
- CVE-2026-100758Sandbox escape in the DOM: Navigation component. This vulner…9.6
- CVE-2026-100759Uninitialized memory in the Storage: Quota Manager component…8.1
- CVE-2026-100760Sandbox escape in the Security: Process Sandboxing component…9.6
- CVE-2026-100761Privilege escalation due to use-after-free in the Graphics: …8.8
- CVE-2026-100762Sandbox escape due to use-after-free in the DOM: Content Pro…9.6
- CVE-2026-100763Incorrect boundary conditions in the Graphics: WebGPU compon…9.1
Are you affected by CVE-2026-100757?
Run a free Strix scan to check your systems for this vulnerability.
Scan your code nowSource: NVD / NIST