Mozilla Thunderbird up to 159 Attachment information disclosure

Summaryinfo

A vulnerability classified as problematic was found in Mozilla Thunderbird up to 159. This affects an unknown function of the component Attachment Handler. Executing a manipulation can lead to information disclosure. This vulnerability is handled as CVE-2026-126132. The attack can be executed remotely. There is not any exploit available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability was found in Mozilla Thunderbird up to 159. It has been declared as problematic. This vulnerability affects an unknown function of the component Attachment Handler. The manipulation with an unknown input leads to a information disclosure vulnerability. The CWE definition for the vulnerability is CWE-200. The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information. As an impact it is known to affect confidentiality. CVE summarizes:

When a message was forwarded inline, edited as new, or had an attachment dragged into a compose window, a specially crafted link attachment (a .desktop file on Linux, or a .url or .lnk file on Windows) was replaced with the content of the file or URL it pointed to when the message was saved or sent. This could disclose local files, or content from the user's network, to the message recipients or to the mail provider. This bug only affects Thunderbird on Linux and Windows. Other operating systems are unaffected. This vulnerability was fixed in Thunderbird 160.

The advisory is available at bugzilla.mozilla.org. This vulnerability was named CVE-2026-126132 since 11/10/2026. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. Successful exploitation requires user interaction by the victim. The technical details are unknown and an exploit is not available. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 11/10/2026). This vulnerability is assigned to T1592 by the MITRE ATT&CK project.

Upgrading to version 160 eliminates this vulnerability.

If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Type

• Mail Client Software

Vendor

• Mozilla

Name

• Thunderbird

Version

• 159

License

• open-source

Website

• Vendor: https://www.mozilla.org/

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CPE 2.2info

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If you want to get best quality of vulnerability data, you may have to visit VulDB.

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