Vulnerability record · CVE-2004-2491 · published 31 December 2004

CVE-2004-2491: Opera browser race condition vulnerability

Opera · Opera Browser

A race condition in Opera web browser 7.53 Build 3850 causes Opera to fill in the address bar before the page has been loaded, which allows remote attackers to spoof the URL in the address bar via the window.open and location.replace HTML parameters, which facilitates phishing attacks.

2.6 CVSS 2.0 Low EPSS 6.3% · top 6.6% CWE-362 · Race condition

2.6CVSS 2.0 base score

6.3%EPSS exploitation probability, 30 days

NoNot in CISA KEV

1Affected product versions listed by NVD

12References, 6 tagged exploit

16 Jun 2026Last modified by NVD

Description

AV:N/AC:H/Au:N/C:N/I:P/A:N

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

Opera Browser Opera

References

Link	Tags
http://archives.neohapsis.com/archives/fulldisclosure/2004-07/1056.html	Broken LinkExploit
http://secunia.com/advisories/12162	Broken LinkPatch
http://www.opera.com/windows/changelogs/754/	Broken LinkPatch
http://www.osvdb.org/8317	Broken LinkExploit
http://www.securityfocus.com/bid/10810	Broken LinkExploitPatchThird Party AdvisoryVDB Entry
https://exchange.xforce.ibmcloud.com/vulnerabilities/16816	Third Party AdvisoryVDB Entry
http://archives.neohapsis.com/archives/fulldisclosure/2004-07/1056.html	Broken LinkExploit
http://secunia.com/advisories/12162	Broken LinkPatch
http://www.opera.com/windows/changelogs/754/	Broken LinkPatch
http://www.osvdb.org/8317	Broken LinkExploit
http://www.securityfocus.com/bid/10810	Broken LinkExploitPatchThird Party AdvisoryVDB Entry
https://exchange.xforce.ibmcloud.com/vulnerabilities/16816	Third Party AdvisoryVDB Entry

Track CVE-2004-2491 inside VULONE

Watch it alongside the ransomware crews, C2 infrastructure and forum chatter that reference it, query it through the API and pull it into your SIEM over TAXII.

Start free Open in platform

Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

10.0CVE-2013-3211Opera browser vulnerabilityUnspecified vulnerability in Opera before 12.15 has unknown impact and attack vectors, related to a "moderately severe issue."EPSS 1.7%19 Apr 2013 10.0CVE-2012-4145Opera browser vulnerabilityUnspecified vulnerability in Opera before 12.01 on Windows and UNIX, and before 11.66 and 12.x before 12.01 on Mac OS X, has unknown impact and attac…EPSS 2.2%6 Aug 2012 10.0CVE-2012-3559Opera browser vulnerabilityUnspecified vulnerability in Opera before 12.00 on Mac OS X has unknown impact and attack vectors, related to a "moderate severity issue."EPSS 1.4%14 Jun 2012 10.0CVE-2012-3561Opera browser memory buffer overflow vulnerabilityOpera before 11.64 does not properly allocate memory for URL strings, which allows remote attackers to execute arbitrary code or cause a denial of se…EPSS 5.2%14 Jun 2012 10.0CVE-2011-4683Opera browser vulnerabilityUnspecified vulnerability in Opera before 11.60 has unknown impact and attack vectors, related to a "moderately severe issue."EPSS 2.0%7 Dec 2011 10.0CVE-2011-4684Opera browser vulnerabilityOpera before 11.60 does not properly handle certificate revocation, which has unspecified impact and remote attack vectors related to "corner cases."EPSS 5.7%7 Dec 2011 10.0CVE-2011-2610Opera browser vulnerabilityUnspecified vulnerability in Opera before 11.50 has unknown impact and attack vectors, related to a "moderately severe issue."EPSS 2.1%1 Jul 2011 10.0CVE-2011-2628Opera browser improper input validation vulnerabilityOpera before 11.11 does not properly implement FRAMESET elements, which allows remote attackers to execute arbitrary code or cause a denial of servic…EPSS 13%1 Jul 2011

Source: NIST National Vulnerability Database (record CVE-2004-2491), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.