CVE-2026-8971: Same-Origin Policy Bypass in Firefox JAR Component
CVE-2026-8971 Published on May 19, 2026
Same-origin policy bypass in the Networking: JAR component
Same-origin policy bypass in the Networking: JAR component. This vulnerability was fixed in Firefox 151 and Thunderbird 151.
Vulnerability Analysis
CVE-2026-8971 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 have a small impact on confidentiality and integrity, and no impact on availability.
Weakness Type
Origin Validation Error
The software does not properly verify that the source of data or communication is valid.
Products Associated with CVE-2026-8971
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Affected Versions
Mozilla Firefox:- Version 151, <= * is unaffected.
- Version 151, <= * 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.