Mozilla Thunderbird vulnerabilities

CVE-2025-4918 [CRITICAL] CWE-125 CVE-2025-4918: An attacker was able to perform an out-of-bounds read or write on a JavaScript `Promise` object. Thi An attacker was able to perform an out-of-bounds read or write on a JavaScript `Promise` object. This vulnerability was fixed in Firefox 138.0.4, Firefox ESR 128.10.1, Firefox ESR 115.23.1, Thunderbird 128.10.2, and Thunderbird 138.0.2.

CVE-2025-4919 [HIGH] CWE-125 CVE-2025-4919: An attacker was able to perform an out-of-bounds read or write on a JavaScript object by confusing a An attacker was able to perform an out-of-bounds read or write on a JavaScript object by confusing array index sizes. This vulnerability was fixed in Firefox 138.0.4, Firefox ESR 128.10.1, Firefox ESR 115.23.1, Thunderbird 128.10.2, and Thunderbird 138.0.2.

CVE-2025-3909 [HIGH] CWE-356 CVE-2025-3909: Thunderbird's handling of the X-Mozilla-External-Attachment-URL header can be exploited to execute J 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

CVE-2025-3875 [HIGH] CWE-290 CVE-2025-3875: Thunderbird parses addresses in a way that can allow sender spoofing in case the server allows an in 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 in Thunderbird 128.10.1 and Thunderbird 138.0.1.

CVE-2025-3932 [MEDIUM] CWE-288 CVE-2025-3932: It was possible to craft an email that showed a tracking link as an attachment. If the user attempte 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 head

CVE-2025-4083 [CRITICAL] CWE-653 CVE-2025-4083: A process isolation vulnerability in Thunderbird stemmed from improper handling of javascript: URIs, 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 was fixed in Firefox 138, Firefox ESR 128.10, Firefox ESR 115.23, Thunderbird 138, and T

CVE-2025-4091 [HIGH] CWE-119 CVE-2025-4091: Memory safety bugs present in Firefox 137, Thunderbird 137, Firefox ESR 128.9, and Thunderbird 128.9 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 was fixed in Firefox 138, Firefox ESR 128.10, Thunderbird 138, and Thunderbi

CVE-2025-4093 [HIGH] CWE-119 CVE-2025-4093: Memory safety bug present in Firefox ESR 128.9, and Thunderbird 128.9. This bug showed evidence of m 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 was fixed in Firefox ESR 128.10 and Thunderbird 128.10.

CVE-2025-4085 [HIGH] CWE-269 CVE-2025-4085: An attacker with control over a content process could potentially leverage the privileged UITour act An attacker with control over a content process could potentially leverage the privileged UITour actor to leak sensitive information or escalate privileges. This vulnerability was fixed in Firefox 138 and Thunderbird 138.

CVE-2025-2817 [HIGH] CWE-22 CVE-2025-2817: Thunderbird's update mechanism allowed a medium-integrity user process to interfere with the SYSTEM- 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

CVE-2025-4092 [MEDIUM] CWE-119 CVE-2025-4092: Memory safety bugs present in Firefox 137 and Thunderbird 137. Some of these bugs showed evidence of Memory safety bugs present in Firefox 137 and Thunderbird 137. 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 was fixed in Firefox 138 and Thunderbird 138.

CVE-2025-4082 [MEDIUM] CWE-125 CVE-2025-4082: Modification of specific WebGL shader attributes could trigger an out-of-bounds read, which, when ch 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 was fixed in Firefox 138, Firefox ESR 128.10, Firefox ESR 115.23, Th

CVE-2025-4088 [MEDIUM] CWE-352 CVE-2025-4088: A security vulnerability in Thunderbird allowed malicious sites to use redirects to send credentiale A security vulnerability in Thunderbird allowed malicious sites to use redirects to send credentialed requests to arbitrary endpoints on any site that had invoked the Storage Access API. This enabled potential Cross-Site Request Forgery attacks across origins. This vulnerability was fixed in Firefox 138 and Thunderbird 138.

CVE-2025-4087 [MEDIUM] CWE-125 CVE-2025-4087: A vulnerability was identified in Thunderbird where XPath parsing could trigger undefined behavior d 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 was fixed in Firefox 138, Firefox ESR 128.10, Thunderbird 138, and Thunderbird 128.10.

CVE-2025-4089 [MEDIUM] CWE-77 CVE-2025-4089: Due to insufficient escaping of special characters in the "copy as cURL" feature, an attacker could Due to insufficient escaping of 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 vulnerability was fixed in Firefox 138 and Thunderbird 138.

CVE-2025-4086 [MEDIUM] CWE-451 CVE-2025-4086: A specially crafted filename containing a large number of encoded newline characters could obscure t A specially crafted filename containing a large number of encoded newline characters could obscure the file's extension when displayed in the download dialog. *This bug only affects Thunderbird for Android. Other versions of Thunderbird are unaffected.*. This vulnerability was fixed in Firefox 138 and Thunderbird 138.

CVE-2025-4090 [MEDIUM] CWE-532 CVE-2025-4090: A vulnerability existed in Thunderbird for Android where potentially sensitive library locations wer A vulnerability existed in Thunderbird for Android where potentially sensitive library locations were logged via Logcat. This vulnerability was fixed in Firefox 138 and Thunderbird 138.

CVE-2025-4084 [MEDIUM] CWE-116 CVE-2025-4084: Due to insufficient escaping of the special characters in the "copy as cURL" feature, an attacker co 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 was fixed in Firefox ESR 128.10, Firef

CVE-2025-3523 [MEDIUM] CWE-451 CVE-2025-3523: When an email contains multiple attachments with external links via the X-Mozilla-External-Attachmen 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 was fixed in Thunder

CVE-2025-2830 [MEDIUM] CWE-22 CVE-2025-2830: By crafting a malformed file name for an attachment in a multipart message, an attacker can trick Th By crafting a malformed file name for an attachment in a multipart message, an attacker can trick Thunderbird into including a directory listing of /tmp when the message is forwarded or edited as a new message. This vulnerability could allow attackers to disclose sensitive information from the victim's system. This vulnerability is not limited to Linux