Mozilla: >> Thunderbird >> 128.1.0 Security Vulnerabilities
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 pages listed in the X-Mozilla-External-Attachment-URL header of an email. This vulnerability affects Thunderbird < 128.10.1 and Thunderbird < 138.0.1.
CVSS Score
6.5
EPSS Score
0.0
Published
2025-05-14
A process isolation vulnerability in Thunderbird stemmed from improper handling of javascript: URIs, which could allow content to execute in the top-level document's process instead of the intended frame, potentially enabling a sandbox escape. This vulnerability affects Firefox < 138, Firefox ESR < 128.10, Firefox ESR < 115.23, Thunderbird < 138, and Thunderbird < 128.10.
CVSS Score
9.1
EPSS Score
0.001
Published
2025-04-29
Due to insufficient escaping of the special characters 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.
*This bug only affects Firefox for Windows. Other versions of Firefox are unaffected.* This vulnerability affects Firefox ESR < 128.10, Firefox ESR < 115.23, and Thunderbird < 128.10.
CVSS Score
5.7
EPSS Score
0.0
Published
2025-04-29
A vulnerability was identified in Thunderbird where XPath parsing could trigger undefined behavior due to missing null checks during attribute access. This could lead to out-of-bounds read access and potentially, memory corruption. This vulnerability affects Firefox < 138, Firefox ESR < 128.10, Thunderbird < 138, and Thunderbird < 128.10.
CVSS Score
6.5
EPSS Score
0.001
Published
2025-04-29
Memory safety bugs present in Firefox 137, Thunderbird 137, Firefox ESR 128.9, and Thunderbird 128.9. 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 < 138, Firefox ESR < 128.10, Thunderbird < 138, and Thunderbird < 128.10.
CVSS Score
6.5
EPSS Score
0.001
Published
2025-04-29
Memory safety bug present in Firefox ESR 128.9, and Thunderbird 128.9. This bug showed evidence of memory corruption and we presume that with enough effort this could have been exploited to run arbitrary code. This vulnerability affects Firefox ESR < 128.10 and Thunderbird < 128.10.
CVSS Score
6.5
EPSS Score
0.001
Published
2025-04-29
Modification of specific WebGL shader attributes could trigger an out-of-bounds read, which, when chained with other vulnerabilities, could be used to escalate privileges.
*This bug only affects Thunderbird for macOS. Other versions of Thunderbird are unaffected.* This vulnerability affects Firefox < 138, Firefox ESR < 128.10, Firefox ESR < 115.23, Thunderbird < 138, and Thunderbird < 128.10.
CVSS Score
5.9
EPSS Score
0.001
Published
2025-04-29
Thunderbird's update mechanism allowed a medium-integrity user process to interfere with the SYSTEM-level updater by manipulating the file-locking behavior. By injecting code into the user-privileged process, an attacker could bypass intended access controls, allowing SYSTEM-level file operations on paths controlled by a non-privileged user and enabling privilege escalation. This vulnerability affects Firefox < 138, Firefox ESR < 128.10, Firefox ESR < 115.23, Thunderbird < 138, and Thunderbird < 128.10.
CVSS Score
8.8
EPSS Score
0.001
Published
2025-04-29
Thunderbird processes the X-Mozilla-External-Attachment-URL header to handle attachments which can be hosted externally. When an email is opened, Thunderbird accesses the specified URL to determine file size, and navigates to it when the user clicks the attachment. Because the URL is not validated or sanitized, it can reference internal resources like chrome:// or SMB share file:// links, potentially leading to hashed Windows credential leakage and opening the door to more serious security issues. This vulnerability affects Thunderbird < 137.0.2 and Thunderbird < 128.9.2.
CVSS Score
6.3
EPSS Score
0.001
Published
2025-04-15
When an email contains multiple attachments with external links via the X-Mozilla-External-Attachment-URL header, only the last link is shown when hovering over any attachment. Although the correct link is used on click, the misleading hover text could trick users into downloading content from untrusted sources. This vulnerability affects Thunderbird < 137.0.2 and Thunderbird < 128.9.2.
CVSS Score
6.4
EPSS Score
0.001
Published
2025-04-15