CVE-2026-84139
Low
No strong exploitation signal.
CVSS base
6.1
MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
EPSS — probability of exploitation (30 days)
0.2%
7.8th percentile
CISA KEV
Not listed
Weakness / dates
CWE-1021
Published 2026-09-01 · modified 2026-09-03
CVSS breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
| Attack Vector | N | Network |
| Attack Complexity | L | Low |
| Privileges Required | N | None |
| User Interaction | R | Required |
| Scope | C | Changed |
| Confidentiality | L | Low |
| Integrity | L | Low |
| Availability | N | None |
Timeline
- 2026-09-01 — Published (NVD)
- 2026-09-03 — Last modified (NVD)
Description
Clickjacking issue in the DOM: Events component. This vulnerability was fixed in Firefox 155, Firefox ESR 153.2, Thunderbird 155, and Thunderbird 153.2.