CVE-2026-84137CWE-346CWE-451

CVE-2026-84137

Medium · published September 1, 2026

CVSS v3.1
4.3
EPSS
0%
Percentile
2.3
In the wild
Unconfirmed
What it is

Spoofing issue in the DOM: Core & HTML component. This vulnerability was fixed in Firefox 155, Firefox ESR 153.2, Thunderbird 155, and Thunderbird 153.2.

The record
Technical detail
CVSS v3.1
4.3 · MEDIUM
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N
CVSS v4.0
Not supplied
EPSS
0.00129 · 2.3th percentile
Weaknesses
CWE-346 · Origin Validation Error; CWE-451 · User Interface (UI) Misrepresentation of Critical Information
Published
2026-09-01T17:20Z
Affected products (4)
ProductVersionsFixed in
mozilla/firefox< 153.2.0153.2.0
mozilla/firefox≥ 154.0.0, < 155.0.0155.0.0
mozilla/thunderbird< 153.2.0153.2.0
mozilla/thunderbird≥ 154.0, < 155.0155.0
References (5)
https://bugzilla.mozilla.org/show_bug.cgi?id=2051146 · [email protected]https://www.mozilla.org/security/advisories/mfsa2026-82/ · [email protected]https://www.mozilla.org/security/advisories/mfsa2026-85/ · [email protected]https://www.mozilla.org/security/advisories/mfsa2026-86/ · [email protected]https://www.mozilla.org/security/advisories/mfsa2026-88/ · [email protected]
EPSS history
Timeline
  • 03 SEP 03:32Z
    EPSS moved — → 0%
    epss
  • 01 SEP 12:19Z
    Spoofing issue in the DOM: Core & HTML component
    cvelistv5