Memory corruption bugs in Firefox 153
CVE-2026-74989 Published on August 18, 2026
Internally found bugs fixed in Thunderbird 154
Internally found bugs present in 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. This vulnerability was fixed in Firefox 154 and Thunderbird 154.
Vulnerability Analysis
CVE-2026-74989 can be exploited with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to be critical as this vulnerability has a high impact to the confidentiality, integrity and availability of this component.
Weakness Type
What is a Buffer Overflow Vulnerability?
The software performs operations on a memory buffer, but it can read from or write to a memory location that is outside of the intended boundary of the buffer.
CVE-2026-74989 has been classified to as a Buffer Overflow vulnerability or weakness.
Products Associated with CVE-2026-74989
stack.watch emails you whenever new vulnerabilities are published in Mozilla Firefox or Mozilla Thunderbird. Just hit a watch button to start following.
Affected Versions
Mozilla Firefox:- Version 154, <= * is unaffected.
- Version 154, <= * is unaffected.