CVE-2026-100779
HIGHCVSS 8.8/10EPSS 0.34%
Last modified
CVE-2026-100779 is a high-severity vulnerability rated 8.8/10 on the CVSS scale. Use-after-free in the XSLT 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 XSLT 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 | < 157.0.0 |
| Mozilla | Firefox | >= 115.1.0, < 115.42.0 |
| Mozilla | Firefox | >= 140.0, < 140.17.0 |
| Mozilla | Firefox | >= 153.0, < 153.4.0 |
| Mozilla | Thunderbird | < 157.0 |
| Mozilla | Thunderbird | >= 140.0, < 140.17.0 |
| Mozilla | Thunderbird | >= 153.0, < 153.4.0 |
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=2068417Permissions 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-2026-100779?
Use-after-free in the XSLT 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-2026-100779?
CVE-2026-100779 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-2026-100779?
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-2026-100773Use-after-free in the Storage: IndexedDB component. This vul…8.8
- CVE-2026-100774Use-after-free in the DOM: Core & HTML component. This vulne…8.8
- CVE-2026-100775Sandbox escape in the Graphics component. This vulnerability…9.6
- CVE-2026-100776Use-after-free in the JavaScript: WebAssembly component. Thi…8.8
- CVE-2026-100777Use-after-free in the Graphics: Canvas2D component. This vul…8.8
- CVE-2026-100778Sandbox escape due to use-after-free in the DOM: Core & HTML…9.6
- CVE-2026-10078A flaw was found in the Quay config-tool's GitLab OAuth vali…2.7
- CVE-2026-100780Use-after-free in the DOM: Core & HTML component. This vulne…8.8
- CVE-2026-100781Sandbox escape due to incorrect boundary conditions in the G…9.6
- CVE-2026-100782Privilege escalation due to incorrect boundary conditions in…8.8
- CVE-2026-100783Uninitialized memory in the Audio/Video component. This vuln…4.3
- CVE-2026-100784Use-after-free in the Layout: Text and Fonts component. This…8.8
Are you affected by CVE-2026-100779?
Run a free Strix scan to check your systems for this vulnerability.
Scan your code nowSource: NVD / NIST