CVE-2025-3909
CVE.org · Published
- Record status
- Published
- Identifier year (not publication year)
- 2025
- Source publication
- Source updated
- Imported by cveboard
- Source snapshot
- cve_2026-10-24_midnight_baseline ·
CNA source text (English)
JavaScript Execution via Spoofed PDF Attachment and file:/// Link
Thunderbird's handling of the X-Mozilla-External-Attachment-URL header can be exploited to execute JavaScript in the file:/// context. By crafting a nested email attachment (message/rfc822) and setting its content type to application/pdf, Thunderbird may incorrectly render it as HTML when opened, allowing the embedded JavaScript to run without requiring a file download. This behavior relies on Thunderbird auto-saving the attachment to /tmp and linking to it via the file:/// protocol, potentially enabling JavaScript execution as part of the HTML. This vulnerability was fixed in Thunderbird 128.10.1 and Thunderbird 138.0.1.
Scoped product and version facts
Fix information unknown; no fixed version is derived here. Missing information does not prove that no fix exists.
Exploitation unknown; this catalogue does not assess exploitation.
Thunderbird
- Vendor
- Mozilla
- Product
- Thunderbird
- Platforms
- Unknown
- Default status
Unknown
| Version (version) | Status (status) | Version scheme (versionType) | Exclusive end (lessThan) | Inclusive end (lessThanOrEqual) | Status changes (at → status) |
|---|---|---|---|---|---|
| 128.10.1 | unaffected | rpm | Unavailable | 128.* | None listed |
| 138.0.1 | unaffected | rpm | Unavailable | * | None listed |