Medium 4.3Published Aug 6, 2012

CVE-2012-4142Opera before 12.01 on Windows and UNIX, and before 11.66 and 12.x before 12.01 on Mac OS X, ignores some characters in HTML documents in unspecified circumstances, which makes it easier for remote at…

Updated under an hour ago (Nov 2, 2026, 12:10 AM ET)

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Opera before 12.01 on Windows and UNIX, and before 11.66 and 12.x before 12.01 on Mac OS X, ignores some characters in HTML documents in unspecified circumstances, which makes it easier for remote attackers to conduct cross-site scripting (XSS) attacks via a crafted document.

CVSS: 4.3 MEDIUM (v2.0, NVD)AV:N/AC:M/Au:N/C:N/I:P/A:N
Weakness (CWE): CWE-79
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Not given
NVD analysis: Modified
Record last updated: Jun 16, 2026
First seen by InfoSec Signals: Nov 1, 2026

Affected products

Affected products

opera opera_browser opera:opera_browser	through 12.00; 12.00; through 11.65; 10.00; 10.00; 10.00; 10.00; 10.01; and 37 more ranges	NVD

References

References

http://www.opera.com/docs/changelogs/mac/1166/
http://www.opera.com/docs/changelogs/mac/1201/
http://www.opera.com/docs/changelogs/unix/1201/
http://www.opera.com/docs/changelogs/windows/1201/
http://www.opera.com/support/kb/view/1026/	vendor-advisory

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.