Description
Thunderbird executed `javascript:` URLs when used in `object` and `embed` tags. This vulnerability was fixed in Firefox 141, Firefox ESR 128.13, Firefox ESR 140.1, Thunderbird 141, Thunderbird 128.13, and Thunderbird 140.1.
Affected products
mozilla: firefox; mozilla: thunderbird
References8
- www.mozilla.org/security/advisories/mfsa2025-56/ Vendor Advisory
- www.mozilla.org/security/advisories/mfsa2025-58/ Vendor Advisory
- www.mozilla.org/security/advisories/mfsa2025-59/ Vendor Advisory
- www.mozilla.org/security/advisories/mfsa2025-61/ Vendor Advisory
- www.mozilla.org/security/advisories/mfsa2025-62/ Vendor Advisory
- www.mozilla.org/security/advisories/mfsa2025-63/ Vendor Advisory
- bugzilla.mozilla.org/show_bug.cgi?id=1928021 Permissions Required
- lists.debian.org/debian-lts-announce/2025/07/msg00016.html
Metrics
- CVSS 3.1
-
8.1
HIGH
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N - EPSS — exploit probability
- 0% percentile: 32 · as of 8 November 2026
- CWE
- CWE-80
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