Firefox ESR Memory Safety Bug (ESR 115.37/140.12) Fixed in 115.38/140.13
CVE-2026-16361 Published on July 21, 2026
Memory safety bugs fixed in Thunderbird ESR 140.13
Memory safety bugs present in Thunderbird ESR 140.12. 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 ESR 115.38, Firefox ESR 140.13, and Thunderbird 140.13.
Vulnerability Analysis
CVE-2026-16361 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-2026-16361 has been classified to as a Buffer Overflow vulnerability or weakness.
Products Associated with CVE-2026-16361
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Affected Versions
Mozilla Firefox:- Version 115.38, <= 115.* is unaffected.
- Version 140.13, <= * is unaffected.
- Version 140.13, <= * is unaffected.
Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.