Threat database

A malicious webpage could repeatedly trigger external URL schemes, causing system prompts or external application launches. This could make Firefox for iOS temporarily unusable until the page is closed. This vulnerability was fixed in Firefox for iOS 155.1.

CVE-2026-84642 is a vulnerability in Mozilla Thunderbird where the mail.allowed_attachment_hostnames setting values were used in a regular expression without proper escaping. This flaw could cause unintended hostnames to match and allow serving of remote attachments. The issue was fixed in Thunderbird versions 155 and 153.2.

CVE-2026-84641 is a use-after-free vulnerability in Mozilla Thunderbird triggered by a malicious IMAP server sending a crafted ID response. This flaw can lead to heap-memory disclosure, with heap contents potentially being saved to prefs.js. The issue was fixed in Thunderbird versions 155, 140.15, and 153.2.

CVE-2026-84640 is a high-severity vulnerability in Mozilla Thunderbird where a maliciously crafted mail header can cause a one-byte read past the end of a buffer. This issue was addressed and fixed in Thunderbird versions 155, 140.15, and 153.2.

CVE-2026-84639 is a critical vulnerability in Mozilla Thunderbird where triggering an error condition in certain MIME bodies causes uninitialized memory to be used. This flaw could lead to a high impact on confidentiality and availability. The issue has been fixed in Thunderbird versions 155, 140.15, and 153.2.

CVE-2026-84637 is a critical vulnerability in Mozilla Thunderbird where malicious calendar invitations can include file URI attachments that launch local or network executables on Windows. This bypasses Thunderbird's usual protections against executable attachments. Additionally, with the new invitation display enabled, the attachment may appear with a misleading filename. The issue was fixed in Thunderbird versions 154 and 153.2.

These are all security issues fixed in the MozillaFirefox-155.0-1.1 package on the GA media of openSUSE Tumbleweed.

Internally found bugs present in Thunderbird 154 and Thunderbird ESR 153.1. Some of these bugs showed evidence of memory corruption or another security-relevant defect and we presume that with enough effort some of these could have been exploited. This vulnerability was fixed in Firefox 155, Firefox ESR 153.2, Thunderbird 155, and Thunderbird 153.2.

Internally found bugs present in Thunderbird 154, Thunderbird ESR 153.1 and Thunderbird ESR 140.14. Some of these bugs showed evidence of memory corruption or another security-relevant defect and we presume that with enough effort some of these could have been exploited. This vulnerability was fixed in Firefox 155, Firefox ESR 140.15, Firefox ESR 153.2, Thunderbird 155, Thunderbird 140.15, and Thunderbird 153.2.

Internally found bugs present in Thunderbird 154. Some of these bugs showed evidence of memory corruption or another security-relevant defect and we presume that with enough effort some of these could have been exploited. This vulnerability was fixed in Firefox 155 and Thunderbird 155.

Integer overflow in the Graphics: ImageLib component. This vulnerability was fixed in Firefox 155, Firefox ESR 153.2, Thunderbird 155, and Thunderbird 153.2.

Site isolation issue in the DOM: Navigation component. This vulnerability was fixed in Firefox 155, Firefox ESR 153.2, Thunderbird 155, and Thunderbird 153.2.

Clickjacking issue in the DOM: Events component. This vulnerability was fixed in Firefox 155, Firefox ESR 153.2, Thunderbird 155, and Thunderbird 153.2.

Denial-of-service in the PDF Viewer component. This vulnerability was fixed in Firefox 155 and Thunderbird 155.

Spoofing issue in the DOM: Core & HTML component. This vulnerability was fixed in Firefox 155, Firefox ESR 153.2, Thunderbird 155, and Thunderbird 153.2.

Other issue in the DOM: Navigation component. This vulnerability was fixed in Firefox 155, Firefox ESR 153.2, Thunderbird 155, and Thunderbird 153.2.

Other issue in Firefox Focus for Android. This vulnerability was fixed in Firefox 155.

Other issue in the Profile Backup component. This vulnerability was fixed in Firefox 155, Firefox ESR 153.2, Thunderbird 155, and Thunderbird 153.2.

Site isolation issue in the DOM: Push Subscriptions component. This vulnerability was fixed in Firefox 155, Firefox ESR 153.2, Thunderbird 155, and Thunderbird 153.2.

Information disclosure in the Networking: HTTP component. This vulnerability was fixed in Firefox 155, Firefox ESR 153.2, Thunderbird 155, and Thunderbird 153.2.