CVE-2026-0887mediumCWE-497

CVE-2026-0887: medium-severity vulnerability in Mozilla Firefox

Clickjacking issue, information disclosure in the PDF Viewer component

Published 13 Jan 2026 · Updated 13 Apr 2026

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13Vexday Risk Score

No sign of exploitation. No public exploitation artifact known so far.

ssvc Trackcvss 4.3epss 0.3%

Clickjacking issue, information disclosure in the PDF Viewer component. This vulnerability was fixed in Firefox 147, Firefox ESR 140.7, Thunderbird 147, and Thunderbird 140.7.

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N

Affected products

Mozilla · Firefox Mozilla · Thunderbird

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References

https://bugzilla.mozilla.org/show_bug.cgi?id=2006500 https://www.mozilla.org/security/advisories/mfsa2026-01/https://www.mozilla.org/security/advisories/mfsa2026-03/https://www.mozilla.org/security/advisories/mfsa2026-04/https://www.mozilla.org/security/advisories/mfsa2026-05/