CVE-2010-1987: Mozilla Firefox

Medium severity, CVSS 5.0. EPSS: 1.5% chance of exploitation in the next 30 days.

Mozilla Firefox 3.6.3 on Windows XP SP3 allows remote attackers to cause a denial of service (memory consumption, out-of-bounds read, and application crash) via JavaScript code that appends long strings to the content of a P element, and performs certain other string concatenation and substring operations, related to the DoubleWideCharMappedString class in USP10.dll and the gfxWindowsFontGroup::GetUnderlineOffset function in xul.dll, a different vulnerability than CVE-2009-1571.

Affected products

• Mozilla Firefox: version 3.6.3 only

Published 2010-05-20. Last modified 2026-06-16.