How severe is CVE-2004-2491?

CVE-2004-2491 has a CVSS 2.0 base score of 2.6, rated low severity.

Is CVE-2004-2491 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 6% (93rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2004-2491?

CVE-2004-2491 affects Opera Opera Browser. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2004-2491?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2004-2491 published?

CVE-2004-2491 was published on 2004-12-31 and last updated on 2026-06-16.

CVE-2004-2491

CVE-2004-2491 is a low-severity vulnerability in Opera Opera Browser with a CVSS 2.0 base score of 2.6. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-362.

Key facts

Severity: Low (CVSS 2.0 base score 2.6)
EPSS exploit prediction: 6% (93rd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-362
Affected product: Opera Opera Browser
Published: 2004-12-31
Last modified: 2026-06-16

Description

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.

Frequently asked questions

What is CVE-2004-2491?: 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.
How severe is CVE-2004-2491?: CVE-2004-2491 has a CVSS 2.0 base score of 2.6, rated low severity.
Is CVE-2004-2491 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 6% (93rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2004-2491?: CVE-2004-2491 affects Opera Opera Browser. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2004-2491?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2004-2491 published?: CVE-2004-2491 was published on 2004-12-31 and last updated on 2026-06-16.

References

Affected products (1)

cpe:2.3:a:opera:opera_browser:*:*:*:*:*:*:*:*

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