CVE-2009-4071: Opera before 10.10, when exception stacktraces are enabled, places scripting error messages from a web site...

Security readout for executives and security teams

CVE-2009-4071 affects Opera browser versions before 10.10 when exception stacktraces are enabled. A website’s script error messages could be exposed to another website, potentially leaking sensitive information or enabling cross-site scripting. Business urgency is mainly for environments still running very old Opera installations. Exposure is likely limited to legacy endpoints using Opera versions earlier than 10.10 with exception stacktraces enabled. Modern environments are unlikely to be affected unless old browser builds remain in kiosks, labs, archived virtual machines, or unmanaged systems. Treat as a targeted legacy cleanup item, not an emergency, unless old Opera is still used on business systems. Prioritize removal or upgrade because the browser is obsolete and the flaw can expose data across sites. Mitigation focus: Upgrade Opera installations to version 10.10 or later where this legacy browser is still present.; If upgrade is not possible, review Opera vendor guidance for supported mitigations.; Verify exception stacktraces are not enabled on any retained vulnerable Opera installations..

Prepared

Jun 28, 2026, 15:13 UTC (UTC+00:00)

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.