Mozilla Firefox vulnerabilities

CVE-2025-49710 [CRITICAL] CWE-190 CVE-2025-49710: An integer overflow was present in `OrderedHashTable` used by the JavaScript engine. This vulnerabil An integer overflow was present in `OrderedHashTable` used by the JavaScript engine. This vulnerability was fixed in Firefox 139.0.4.

CVE-2025-49709 [CRITICAL] CWE-787 CVE-2025-49709: Certain canvas operations could have lead to memory corruption. This vulnerability was fixed in Fire Certain canvas operations could have lead to memory corruption. This vulnerability was fixed in Firefox 139.0.4.

CVE-2025-5268 [HIGH] CWE-119 CVE-2025-5268: Memory safety bugs present in Firefox 138, Thunderbird 138, Firefox ESR 128.10, and Thunderbird 128. 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. This vulnerability was fixed in Firefox 139, Firefox ESR 128.11, Thunderbird 139, and Thunder

CVE-2025-5272 [HIGH] CWE-787 CVE-2025-5272: Memory safety bugs present in Firefox 138 and Thunderbird 138. Some of these bugs showed evidence of Memory safety bugs present in Firefox 138 and Thunderbird 138. 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 139 and Thunderbird 139.

CVE-2025-5270 [HIGH] CWE-319 CVE-2025-5270: In certain cases, SNI could have been sent unencrypted even when encrypted DNS was enabled. This vul In certain cases, SNI could have been sent unencrypted even when encrypted DNS was enabled. This vulnerability was fixed in Firefox 139 and Thunderbird 139.

CVE-2025-5269 [HIGH] CWE-787 CVE-2025-5269: Memory safety bug present in Firefox ESR 128.10, and Thunderbird 128.10. This bug showed evidence of 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. This vulnerability was fixed in Firefox ESR 128.11 and Thunderbird 128.11.

CVE-2025-5265 [MEDIUM] CWE-77 CVE-2025-5265: Due to insufficient escaping of the ampersand character in the “Copy as cURL” feature, an attacker c Due to insufficient escaping of the ampersand 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. *This bug only affects Firefox for Windows. Other versions of Firefox are unaffected.*. This vulnerability was fixed in Firefox 139, Firefox ESR

CVE-2025-5263 [MEDIUM] CWE-346 CVE-2025-5263: Error handling for script execution was incorrectly isolated from web content, which could have allo Error handling for script execution was incorrectly isolated from web content, which could have allowed cross-origin leak attacks. This vulnerability was fixed in Firefox 139, Firefox ESR 115.24, Firefox ESR 128.11, Thunderbird 139, and Thunderbird 128.11.

CVE-2025-5266 [MEDIUM] CWE-200 CVE-2025-5266: Script elements loading cross-origin resources generated load and error events which leaked informat Script elements loading cross-origin resources generated load and error events which leaked information enabling XS-Leaks attacks. This vulnerability was fixed in Firefox 139, Firefox ESR 128.11, Thunderbird 139, and Thunderbird 128.11.

CVE-2025-5267 [MEDIUM] CWE-1021 CVE-2025-5267: A clickjacking vulnerability could have been used to trick a user into leaking saved payment card de A clickjacking vulnerability could have been used to trick a user into leaking saved payment card details to a malicious page. This vulnerability was fixed in Firefox 139, Firefox ESR 128.11, Thunderbird 139, and Thunderbird 128.11.

CVE-2025-5264 [MEDIUM] CWE-77 CVE-2025-5264: Due to insufficient escaping of the newline character in the “Copy as cURL” feature, an attacker cou 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. This vulnerability was fixed in Firefox 139, Firefox ESR 115.24, Firefox ESR 128.11, Thunderbird 139, and Thunderbird 128.11.

CVE-2025-5271 [MEDIUM] CWE-116 CVE-2025-5271: Previewing a response in Devtools ignored CSP headers, which could have allowed content injection at Previewing a response in Devtools ignored CSP headers, which could have allowed content injection attacks. This vulnerability was fixed in Firefox 139 and Thunderbird 139.

CVE-2025-5020 [MEDIUM] CWE-939 CVE-2025-5020: Opening maliciously-crafted URLs in Firefox from other apps such as Safari could have allowed attack Opening maliciously-crafted URLs in Firefox from other apps such as Safari could have allowed attackers to spoof website addresses if the URLs utilized non-HTTP schemes used internally by the Firefox iOS client. This vulnerability was fixed in Firefox for iOS 139.

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-2025-4083 [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-2025-4093 [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-2025-4091 [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-2025-2817 [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