CVEFinder.io

CVE-2026-84120

🔶 medium
🔍 Scan for this CVE
Summary

Use-after-free in the Audio/Video component. This vulnerability was fixed in Firefox 155, Firefox ESR 115.40, Firefox ESR 140.15, Firefox ESR 153.2, Thunderbird 155, Thunderbird 140.15, and Thunderbird 153.2.

CVSS Score
5.4
Medium
EPSS Score
0.2
Exploit Probability
Published Date
2026-09-01
First Seen: 2026-09-03
📊 Relative Risk Intelligence

This CVE is Lower Risk - more severe than 22.2% of all 364,858 vulnerabilities in our database.

#283,815
Below average severity
Severity Percentile
🎯 CISA SSVC Assessment Updated: Sep 1, 2026
🔍 Exploitation Status
None
No known exploits
⚙️ Automatable
NO
Requires human interaction
💥 Technical Impact
Partial
Limited system impact
🏆 Discovered By
Ukyo Akai
SSVC data provided by CISA
Last Modified 2026-09-02
Source NVD 🔗
CVSS Vector 3.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N
CWE IDs (Weakness Types)
CWE-416

📦 Affected Products 7

Vendor Product Status Affected Versions
mozilla firefox Affected
< 115.40.0
mozilla firefox Affected
> 116.0 < 140.15.0
mozilla firefox Affected
> 141.0.0 < 153.2.0
mozilla firefox Affected
> 154.0.0 < 155.0.0
mozilla thunderbird Affected
< 140.15.0
mozilla thunderbird Affected
> 141.0 < 153.2.0
mozilla thunderbird Affected
> 154.0 < 155.0

🔗 References 8

https://bugzilla.mozilla.org/show_bug.cgi?id=2058911
Permissions Required
https://www.mozilla.org/security/advisories/mfsa2026...
Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026...
Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026...
Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026...
Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026...
Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026...
Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026...
Vendor Advisory

🔗 Related CVEs 6

CVE ID Severity CVSS EPSS Summary Published
CVE-2026-100777 ⚠️ high 8.8 0.3 Use-after-free in the Graphics: Canvas2D component. This vulnerability was fixed in Firefox ESR 153.4, Thunderbird 157, ... 2026-09-29
CVE-2026-100778 ⛔ critical 9.6 0.3 Sandbox escape due to use-after-free in the DOM: Core & HTML component. This vulnerability was fixed in Firefox ESR 153.... 2026-09-29
CVE-2026-100779 ⚠️ high 8.8 0.3 Use-after-free in the XSLT component. This vulnerability was fixed in Firefox ESR 153.4, Thunderbird 157, Thunderbird 14... 2026-09-29
CVE-2026-100780 ⚠️ high 8.8 0.3 Use-after-free in the DOM: Core & HTML component. This vulnerability was fixed in Firefox ESR 153.4, Thunderbird 157, Th... 2026-09-29
CVE-2026-100781 ⛔ critical 9.6 0.4 Sandbox escape due to incorrect boundary conditions in the Graphics: WebRender component. This vulnerability was fixed i... 2026-09-29
CVE-2026-100782 ⚠️ high 8.8 0.3 Privilege escalation due to incorrect boundary conditions in the Graphics component. This vulnerability was fixed in Fir... 2026-09-29
These CVEs affect the same products