Firefox NSS boundary overflow (before 150/140.10)
CVE-2026-6766 Published on April 21, 2026
Incorrect boundary conditions in the Libraries component in NSS
Incorrect boundary conditions in the Libraries component in NSS. This vulnerability was fixed in Firefox 150, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.
Vulnerability Analysis
CVE-2026-6766 is exploitable 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 have a high impact on confidentiality, with no impact on integrity and availability.
Weakness Type
Improper Check for Unusual or Exceptional Conditions
The software does not check or incorrectly checks for unusual or exceptional conditions that are not expected to occur frequently during day to day operation of the software.
Products Associated with CVE-2026-6766
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Affected Versions
Mozilla Firefox:- Version 140.10, <= 140.* is unaffected.
- Version 150, <= * is unaffected.
- Version 140.10, <= 140.* is unaffected.
- Version 150, <= * is unaffected.