Firefox/Thunderbird <=146, ESR <140.7: Clickjacking & info disclosure via PDF Viewer
CVE-2026-0887 Published on January 13, 2026
Clickjacking issue, information disclosure in the PDF Viewer component
Clickjacking issue, information disclosure in the PDF Viewer component. This vulnerability affects Firefox < 147, Firefox ESR < 140.7, Thunderbird < 147, and Thunderbird < 140.7.
Vulnerability Analysis
CVE-2026-0887 can be exploited 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 have a small impact on confidentiality, a small impact on integrity and availability.
Weakness Type
Exposure of Sensitive System Information to an Unauthorized Control Sphere
The application does not properly prevent sensitive system-level information from being accessed by unauthorized actors who do not have the same level of access to the underlying system as the application does.
Products Associated with CVE-2026-0887
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Affected Versions
Mozilla Firefox:- Version unspecified and below 147 is affected.
- Version unspecified and below 140.7 is affected.
- Version unspecified and below 147 is affected.
- Version unspecified and below 140.7 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.