Advisory: Combinations of right-to-left text and negative margins can crash Opera
Combinations of right-to-left text and negative marginsin HTML code can crash Opera.
Severity: Not a security issue.
Right-to-left scripts, for example Arabic, are handled bythe so-called "bidi" (bidirectional text) support in Opera.Bidi allows left-to-right and right-to-left scripts tobe combined in the same document, even on the same line.
A negative margin value inside a block containing right-to-left text can cause the layout engine to follow a nullpointer, leading to a crash.
This crash can not be used to run arbitrary code and shouldnot be considered a security issue.