Firefox Same-origin policy bypass in JAR component before 148/ESR 140.8
CVE-2026-2790 Published on February 24, 2026
Same-origin policy bypass in the Networking: JAR component
Same-origin policy bypass in the Networking: JAR component. This vulnerability affects Firefox < 148 and Firefox ESR < 140.8.
Vulnerability Analysis
CVE-2026-2790 is exploitable with network access, requires 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 very high.
Weakness Type
Origin Validation Error
The software does not properly verify that the source of data or communication is valid.
Products Associated with CVE-2026-2790
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Affected Versions
Mozilla Firefox:- Version unspecified and below 148 is affected.
- Version unspecified and below 140.8 is affected.
- Version unspecified and below 148 is affected.
- Version unspecified and below 140.8 is affected.
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.