Security Vulnerabilities fixed in Thunderbird 156 — Mozilla

A maliciously constructed mail header could lead to multiple fields being parsed as one, or potential memory safety violations. A maliciously constructed IMAP line could cause an out-of-bounds buffer read. A malicious or compromised IMAP server can trigger an out-of-bounds read in the IMAP respon...

Security Vulnerabilities fixed in Thunderbird 140.9.1 — Mozilla

Memory safety bugs present in Firefox ESR 115.34.0, Firefox ESR 140.9.0, Thunderbird ESR 140.9.0, Firefox 149.0.1 and Thunderbird 149.0.1. 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...

Security Vulnerabilities fixed in Thunderbird 140.7.1 — Mozilla

When a user explicitly requested Thunderbird to decrypt an inline OpenPGP message that was embedded in a text section of an email that was formatted and styled with HTML and CSS, then the decrypted contents were rendered in a context in which the CSS styles from the outer messages were active. If...

Security Vulnerabilities fixed in Thunderbird 128.13 — Mozilla

On 64-bit platforms IonMonkey-JIT only wrote 32 bits of the 64-bit return value space on the stack. Baseline-JIT, however, read the entire 64 bits. On arm64, a WASM brtable instruction with a lot of entries could lead to the label being too far from the instruction causing truncation and incorrec...

The return of frame-injection spoofing — Mozilla

The original frame-injection spoofing bug was fixed in the Mozilla Suite 1.7 and Firefox 0.9 releases. This protection was accidentally bypassed by one of the fixes in the Firefox 1.0.3 and Mozilla Suite 1.7.7 releases...

Showing blocked javascript: popup uses wrong privilege context — Mozilla

When a popup is blocked the user is given the ability to open that one popup through the popup-blocking status bar icon and, in Firefox, through the infobar. If the popup URL were javascript: selecting "Show javascript:..." from the infobar or popup blocking status bar icon menus would run the...

Security Vulnerabilities fixed in Firefox ESR 153.5.1 — Mozilla

Mozilla blocked compromised intermediate eMudhra certificates via OneCRL on the 17th of October which was distributed to clients via RemoteSettings the same day. This update contains the updated OneCRL block list, ensuring clients will block the compromised certificates even if RemoteSettings is...

Security Vulnerabilities fixed in Thunderbird 140.16 — Mozilla

A maliciously constructed mail header could lead to multiple fields being parsed as one, or potential memory safety violations. A maliciously constructed IMAP line could cause an out-of-bounds buffer read. A malicious or compromised IMAP server can trigger an out-of-bounds read in the IMAP respon...

Security Vulnerabilities fixed in Thunderbird 140.15 — Mozilla

Triggering an error condition in certain MIME bodies would cause uninitialized memory to be used. A maliciously constructed mail header could lead to a one byte read past the end of a buffer. A malicious IMAP server can trigger use-after-free and heap-memory disclosure by sending a crafted ID...

Security Vulnerabilities fixed in Firefox ESR 115.42 — Mozilla

Note : We have changed how we publish advisories. We no longer roll all internally identified memory safety vulnerabilities into a single CVE and are now issuing an advisory for every individual bug. CVE-2026-100756: Incorrect boundary conditions in the Audio/Video: Playback component Reporter...

Security Vulnerabilities fixed in Thunderbird 153.1 — Mozilla

Internally found bugs present in Thunderbird ESR 140.13, Thunderbird ESR 153.0 and Thunderbird 153. 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. Internally found bugs...

FTP PASV port-scanning — Mozilla

The FTP protocol includes the PASV passive command which is used by Firefox to request an alternate data port. The specification of the FTP protocol allows the server response to include an alternate server address as well, although this is rarely used in practice...

Security Vulnerabilities fixed in Firefox ESR 115.43 — Mozilla

Note : We have changed how we publish advisories. We no longer roll all internally identified memory safety vulnerabilities into a single CVE and are now issuing an advisory for every individual bug. CVE-2026-109706: Use-after-free in the Storage: IndexedDB component Reporter Mozilla Impact high...

Security Vulnerabilities fixed in Thunderbird 155 — Mozilla

Triggering an error condition in certain MIME bodies would cause uninitialized memory to be used. A maliciously constructed mail header could lead to a one byte read past the end of a buffer. A malicious IMAP server can trigger use-after-free and heap-memory disclosure by sending a crafted ID...

HTTP auth prompt tab spoofing — Mozilla

The HTTP authentication prompt appears above the currently open tab regardless of which tab triggered it. A spoofer who could get a user to open a high value target in another tab might be able to capture the user's ID and password. HTTP auth dialogs are visually distinct from the web form logins...

Security Vulnerabilities fixed in Thunderbird 153.2 — Mozilla

Triggering an error condition in certain MIME bodies would cause uninitialized memory to be used. A maliciously constructed mail header could lead to a one byte read past the end of a buffer. A malicious IMAP server can trigger use-after-free and heap-memory disclosure by sending a crafted ID...

Security Vulnerabilities fixed in Firefox ESR 115.43.1 — Mozilla

Mozilla blocked compromised intermediate eMudhra certificates via OneCRL on the 17th of October which was distributed to clients via RemoteSettings the same day. This update contains the updated OneCRL block list, ensuring clients will block the compromised certificates even if RemoteSettings is...

Security Vulnerabilities fixed in Thunderbird 140.17 — Mozilla

An attacker could cause a heap buffer overflow by getting a user to open an email that is greater than or equal to 2GB in size...

Security Vulnerabilities fixed in Thunderbird 153.5 — Mozilla

A malicious, compromised, or MITM-controlled Exchange server can return a single well-formed SOAP response containing an element with enough attributes to keep Thunderbird's main thread CPU-bound for seconds to hours...

Security Vulnerabilities fixed in Thunderbird 153.4 — Mozilla

An attacker could cause a heap buffer overflow by getting a user to open an email that is greater than or equal to 2GB in size...

Security Vulnerabilities fixed in Thunderbird 158.0.1 — Mozilla

When setting up an account, Thunderbird's Exchange AutoDiscover lookup also queried the domain's AutoDiscover service over plain HTTP. Due to a bug, that unencrypted request included the credentials the user had entered, allowing a network attacker to obtain the user's password. Thunderbird did n...

Security Vulnerabilities fixed in Thunderbird 153.5.1 — Mozilla

When setting up an account, Thunderbird's Exchange AutoDiscover lookup also queried the domain's AutoDiscover service over plain HTTP. Due to a bug, that unencrypted request included the credentials the user had entered, allowing a network attacker to obtain the user's password. Thunderbird did n...

Security Vulnerabilities fixed in Thunderbird 158 — Mozilla

Several buffer-growth sites in libmime performed size arithmetic in 32-bit types without overflow checks. On a sufficiently large message the growth guard could fail open, or the buffer could be reallocated smaller than required, and a subsequent memcpy would then write attacker-controlled data...