CVE-2025-5986

Mozilla Thunderbird is a standalone mail and newsgroup client.

Security Fix(es):

A permission leak could have occurred from a trusted site to an untrusted site via embed or object elements. This vulnerability affects Firefox < 132, Firefox ESR < 128.4, Firefox ESR < 115.17, Thunderbird < 128.4, and Thunderbird < 132.(CVE-2024-10458)

An attacker could have caused a use-after-free when accessibility was enabled, leading to a potentially exploitable crash. This vulnerability affects Firefox < 132, Firefox ESR < 128.4, Firefox ESR < 115.17, Thunderbird < 128.4, and Thunderbird < 132.(CVE-2024-10459)

The origin of an external protocol handler prompt could have been obscured using a data: URL within an iframe. This vulnerability affects Firefox < 132, Firefox ESR < 128.4, Thunderbird < 128.4, and Thunderbird < 132.(CVE-2024-10460)

In multipart/x-mixed-replace responses, Content-Disposition: attachment in the response header was not respected and did not force a download, which could allow XSS attacks. This vulnerability affects Firefox < 132, Firefox ESR < 128.4, Thunderbird < 128.4, and Thunderbird < 132.(CVE-2024-10461)

Truncation of a long URL could have allowed origin spoofing in a permission prompt. This vulnerability affects Firefox < 132, Firefox ESR < 128.4, Thunderbird < 128.4, and Thunderbird < 132.(CVE-2024-10462)

Video frames could have been leaked between origins in some situations. This vulnerability affects Firefox < 132, Firefox ESR < 128.4, Firefox ESR < 115.17, Thunderbird < 128.4, and Thunderbird < 132.(CVE-2024-10463)

Repeated writes to history interface attributes could have been used to cause a Denial of Service condition in the browser. This was addressed by introducing rate-limiting to this API. This vulnerability affects Firefox < 132, Firefox ESR < 128.4, Thunderbird < 128.4, and Thunderbird < 132.(CVE-2024-10464)

A clipboard "paste" button could persist across tabs which allowed a spoofing attack. This vulnerability affects Firefox < 132, Firefox ESR < 128.4, Thunderbird < 128.4, and Thunderbird < 132.(CVE-2024-10465)

By sending a specially crafted push message, a remote server could have hung the parent process, causing the browser to become unresponsive. This vulnerability affects Firefox < 132, Firefox ESR < 128.4, Thunderbird < 128.4, and Thunderbird < 132.(CVE-2024-10466)

Memory safety bugs present in Firefox 131, Firefox ESR 128.3, and Thunderbird 128.3. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 132, Firefox ESR < 128.4, Thunderbird < 128.4, and Thunderbird < 132.(CVE-2024-10467)

Using remote content in OpenPGP encrypted messages can lead to the disclosure of plaintext. This vulnerability affects Thunderbird < 128.4.3 and Thunderbird < 132.0.1.(CVE-2024-11159)

Certain WebGL operations on Apple silicon M series devices could have lead to an out-of-bounds write and memory corruption due to a flaw in Apple's GPU driver.
This bug only affected the application on Apple M series hardware. Other platforms were unaffected. This vulnerability affects Firefox < 133, Firefox ESR < 128.5, Firefox ESR < 115.18, Thunderbird < 133, Thunderbird < 128.5, and Thunderbird < 115.18.(CVE-2024-11691)

An attacker could cause a select dropdown to be shown over another tab; this could have led to user confusion and possible spoofing attacks. This vulnerability affects Firefox < 133, Firefox ESR < 128.5, Thunderbird < 133, and Thunderbird < 128.5.(CVE-2024-11692)

The executable file warning was not presented when downloading .library-ms files.
Note: This issue only affected Windows operating systems. Other operating systems are unaffected. This vulnerability affects…

Mozilla Thunderbird is a standalone mail and newsgroup client.

Security Fix(es):

• thunderbird: Unsolicited File Download, Disk Space Exhaustion, and Credential Leakage via mailbox:/// Links (CVE-2025-5986)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Mozilla Thunderbird is a standalone mail and newsgroup client.

Security Fix(es):

• thunderbird: Unsolicited File Download, Disk Space Exhaustion, and Credential Leakage via mailbox:/// Links (CVE-2025-5986)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Mozilla Thunderbird is a standalone mail and newsgroup client.

Security Fix(es):

• thunderbird: Unsolicited File Download, Disk Space Exhaustion, and Credential Leakage via mailbox:/// Links (CVE-2025-5986)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

A crafted HTML email using mailbox:/// links can trigger automatic, unsolicited downloads of .pdf files to the user's desktop or home directory without prompting, even if auto-saving is disabled. This behavior can be abused to fill the disk with garbage data (e.g. using /dev/urandom on Linux) or to leak Windows credentials via SMB links when the email is viewed in HTML mode. While user interaction is required to download the .pdf file, visual obfuscation can conceal the download trigger. Viewing the email in HTML mode is enough to load external content. This vulnerability was fixed in Thunderbird 128.11.1 and Thunderbird 139.0.2.

Mozilla Thunderbird is a standalone mail and newsgroup client.

Security Fix(es):

• thunderbird: Unsolicited File Download, Disk Space Exhaustion, and Credential Leakage via mailbox:/// Links (CVE-2025-5986)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Mozilla Thunderbird is a standalone mail and newsgroup client.

Security Fix(es):

• thunderbird: Unsolicited File Download, Disk Space Exhaustion, and Credential Leakage via mailbox:/// Links (CVE-2025-5986)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Mozilla Thunderbird is a standalone mail and newsgroup client.

Security Fix(es):

• thunderbird: Unsolicited File Download, Disk Space Exhaustion, and Credential Leakage via mailbox:/// Links (CVE-2025-5986)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

• rebase from Thunderbird 115.4.1 to 140.12.0 ESR

• CVE-2022-3032: When receiving an HTML email that contained an iframe element, which used a srcdoc attribute to define the inner HTML document, remote objects specified in the nested document, for example images or videos, were not blocked

• CVE-2023-0430: Certificate OCSP revocation status was not checked when verifying S/Mime signatures

• CVE-2023-0547: OCSP revocation status of recipient certificates was not checked when sending S/Mime encrypted email, and revoked certificates would be accepted

• CVE-2023-0616: If a MIME email combines OpenPGP and OpenPGP MIME data in a certain way Thunderbird repeatedly attempts to process and display the message, which could cause Thunderbird's user interface to lock up and no longer respond to the user's actions

• CVE-2023-1945: Unexpected data returned from the Safe Browsing API could have led to memory corruption and a potentially exploitable crash

• CVE-2023-4573: When receiving rendering data over IPC mStream could have been destroyed when initialized, which could have led to a use-after-free causing a potentially exploitable crash

• CVE-2023-4574: When creating a callback over IPC for showing the Color Picker window, multiple of the same callbacks could have been created at a time and eventually all simultaneously destroyed as soon as one of the callbacks finished

• CVE-2023-4575: When creating a callback over IPC for showing the File Picker window, multiple of the same callbacks could have been created at a time and eventually all simultaneously destroyed as soon as one of the callbacks finished

• CVE-2023-4577: When UpdateRegExpStatics attempted to access initialStringHeap it could already have been garbage collected prior to entering the function, which could potentially have led to an exploitable crash

• CVE-2023-4578: When calling JS::CheckRegExpSyntax a Syntax Error could have been set which would end in calling convertToRuntimeErrorAndClear. A path in the function could attempt to allocate memory when none is available which would have caused a newly created Out of Memory exception to be mishandled as a Syntax Error

• CVE-2023-4580: Push notifications stored on disk in private browsing mode were not being encrypted potentially allowing the leak of sensitive information

• CVE-2023-4581: Excel .xll add-in files did not have a blocklist entry in Firefox's executable blocklist which allowed them to be downloaded without any warning of their potential harm

• CVE-2023-5169: A compromised content process could have provided malicious data in a PathRecording resulting in an out-of-bounds write, leading to a potentially exploitable crash in a privileged process

• CVE-2023-5171: During Ion compilation, a Garbage Collection could have resulted in a use-after-free condition, allowing an attacker to write two NUL bytes, and cause a potentially exploitable crash

• CVE-2023-5724: Drivers are not always robust to extremely large draw calls and in some cases this scenario could have led to a crash

• CVE-2023-5725: A malicious installed WebExtension could open arbitrary URLs, which under the right circumstance could be leveraged to collect sensitive user data

• CVE-2023-5732: An attacker could have created a malicious link using bidirectional characters to spoof the location in the address bar when visited

• CVE-2023-6204: On some systems—depending on the graphics settings and drivers—it was possible to force an out-of-bounds read and leak memory data into the images created on the canvas element

• CVE-2023-6205: It was possible to cause the use of a MessagePort after it had already been freed, which could potentially have led to an exploitable crash

• CVE-2023-6206: The black fade animation when exiting fullscreen is roughly the length of the anti-clickjacking delay on permission prompts

• CVE-2023-6207: Ownership…

CVE-2025-5262: A double-free could have occurred in vpx_codec_enc_init_multi after a failed allocation when initializing the encoder for WebRTC. This could have caused memory corruption and a potentially exploitable crash. CVE-2025-5263: Error handling for script execution was incorrectly isolated from web content, which could have allowed cross-origin leak attacks. CVE-2025-5264: Due to insufficient escaping of the newline character in the “Copy as cURL” feature, an attacker could trick a user into using this command, potentially leading to local code execution on the user's system. CVE-2025-5266: Script elements loading cross-origin resources generated load and error events which leaked information enabling XS-Leaks attacks. CVE-2025-5267: A clickjacking vulnerability could have been used to trick a user into leaking saved payment card details to a malicious page. CVE-2025-5268: Memory safety bugs present in Firefox 138, Thunderbird 138, Firefox ESR 128.10, and Thunderbird 128.10. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. CVE-2025-5269: Memory safety bug present in Firefox ESR 128.10, and Thunderbird 128.10. This bug showed evidence of memory corruption and we presume that with enough effort this could have been exploited to run arbitrary code. CVE-2025-5986: A crafted HTML email using mailbox:/// links can trigger automatic, unsolicited downloads of .pdf files to the user's desktop or home directory without prompting, even if auto-saving is disabled. This behavior can be abused to fill the disk with garbage data (e.g. using /dev/urandom on Linux) or to leak Windows credentials via SMB links when the email is viewed in HTML mode. While user interaction is required to download the .pdf file, visual obfuscation can conceal the download trigger. Viewing the email in HTML mode is enough to load external content. We can't ship this update to armv7hl architecture, we are investigating the issue and will try to update thunderbird for armv7hl as soon as posible.

These are all security issues fixed in the MozillaThunderbird-128.11.1-2.1 package on the GA media of openSUSE Tumbleweed.

This update for MozillaThunderbird fixes the following issues:

Mozilla Thunderbird 128.11.1

• CVE-2025-5986: Unsolicited File Download, Disk Space Exhaustion, and Credential Leakage via mailbox:/// Links (MFSA 2025-49) (bsc#1244468).

Multiple security issues were discovered in Thunderbird. If a user were tricked into opening a specially crafted website in a browsing context, an attacker could potentially exploit these to cause a denial of service, obtain sensitive information, bypass security restrictions, cross-site tracing, or execute arbitrary code.