The vulnerability of the Thunderbird email client, related to bypassing authentication through spamming, allows a hacker to execute arbitrary code.

The vulnerability of the Thunderbird email client relates to bypassing authentication through spamming when processing the X-Mozilla-External-Attachment-URL header. Exploiting this vulnerability allows a remote attacker to execute arbitrary code...

CVE-2025-4919

An attacker was able to perform an out-of-bounds read or write on a JavaScript object by confusing array index sizes. This vulnerability affects Firefox 138.0.4, Firefox ESR 128.10.1, Firefox ESR 115.23.1, Thunderbird 128.10.2, and Thunderbird 138.0.2...

firefox: thunderbird: Process isolation bypass using "javascript:" URI links in cross-origin frames

A flaw was found in Firefox. The Mozilla Foundation's Security Advisory describes the following issue: A process isolation vulnerability in Firefox stemmed from improper handling of javascript: URIs, which could allow content to execute in the top-level document's process instead of the intended...

firefox: thunderbird: Process isolation bypass using "javascript:" URI links in cross-origin frames

A flaw was found in Firefox. The Mozilla Foundation's Security Advisory describes the following issue: A process isolation vulnerability in Firefox stemmed from improper handling of javascript: URIs, which could allow content to execute in the top-level document's process instead of the intended...

firefox: thunderbird: Process isolation bypass using "javascript:" URI links in cross-origin frames

A flaw was found in Firefox. The Mozilla Foundation's Security Advisory describes the following issue: A process isolation vulnerability in Firefox stemmed from improper handling of javascript: URIs, which could allow content to execute in the top-level document's process instead of the intended...

ROS-20250515-08

A vulnerability in the Thunderbird email client is related to the presence of multiple attachments with external links via the X-Mozilla-External-Attachment-URL header, when hovering over any attachment, only the the last link. Exploiting this vulnerability allows remote attackers, perform a...

CVE-2025-3875

Thunderbird parses addresses in a way that can allow sender spoofing in case the server allows an invalid From address to be used. For example, if the From header contains an invalid value "Spoofed Name ", Thunderbird treats [email protected] as the actual address. This vulnerability was fixed ...

CVE-2025-3909

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,...

CVE-2025-3875

Thunderbird parses addresses in a way that can allow sender spoofing in case the server allows an invalid From address to be used. For example, if the From header contains an invalid value "Spoofed Name ", Thunderbird treats [email protected] as the actual address. This vulnerability affects...

CVE-2025-3909

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,...

CVE-2025-3932

It was possible to craft an email that showed a tracking link as an attachment. If the user attempted to open the attachment, Thunderbird automatically accessed the link. The configuration to block remote content did not prevent that. Thunderbird has been fixed to no longer allow access to web...

UBUNTU-CVE-2025-3875

Thunderbird parses addresses in a way that can allow sender spoofing in case the server allows an invalid From address to be used. For example, if the From header contains an invalid value "Spoofed Name ", Thunderbird treats [email protected] as the actual address. This vulnerability was fixed ...

CVE-2025-3909 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,...

CVE-2025-3909

Thunderbird (email client) is affected by CVE-2025-3909 via the X-Mozilla-External-Attachment-URL header. An attacker could craft a nested message/rfc822 attachment with content type application/pdf, causing Thunderbird to render it as HTML and execute JavaScript in the file:/// context after aut...

CVE-2025-3932

The CVE-2025-3932 issue concerns Thunderbird where an email could display a tracking link as an attachment; when opened, Thunderbird could access the external URL via the X-Mozilla-External-Attachment-URL header despite remote content blocking. Affected products: Thunderbird versions earlier than...

CVE-2025-3932 Tracking Links in Attachments Bypassed Remote Content Blocking

It was possible to craft an email that showed a tracking link as an attachment. If the user attempted to open the attachment, Thunderbird automatically accessed the link. The configuration to block remote content did not prevent that. Thunderbird has been fixed to no longer allow access to web...

CVE-2025-3909

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,...

CVE-2025-3909 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,...

CVE-2025-3875 Sender Spoofing via Malformed From Header in Thunderbird

Thunderbird parses addresses in a way that can allow sender spoofing in case the server allows an invalid From address to be used. For example, if the From header contains an invalid value "Spoofed Name ", Thunderbird treats [email protected] as the actual address. This vulnerability was fixed ...

CVE-2025-3875 Sender Spoofing via Malformed From Header in Thunderbird

Thunderbird parses addresses in a way that can allow sender spoofing in case the server allows an invalid From address to be used. For example, if the From header contains an invalid value "Spoofed Name ", Thunderbird treats [email protected] as the actual address. This vulnerability was fixed ...