Is CVE-2008-5555 being actively exploited?

CVE-2008-5555 is not currently listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

What is the CVSS score for CVE-2008-5555?

CVE-2008-5555 has a CVSS 2.0 base score of 4.3 (MEDIUM).

CVE-2008-5555

MEDIUM · CVSS 4.3EPSS 12.5%EU EUVD

Microsoft Internet Explorer 8.0 Beta 2 relies on the XDomainRequestAllowed HTTP header to authorize data exchange between domains, which allows remote attackers to bypass the product's XSS Filter protection mechanism, and conduct XSS and cross-domain attacks, by injecting this header after a CRLF sequence, related to "XDomainRequest Allowed Injection (XAI)." NOTE: the vendor has reportedly stated that the XSS Filter intentionally does not attempt to "address every conceivable XSS attack scenario."

Key facts

CVSS score: 4.3 (v2.0)
Severity: MEDIUM
CVSS vector: AV:N/AC:M/Au:N/C:N/I:P/A:N
Weakness (CWE): CWE-79
EPSS score: 12.5% (96th percentile)
In CISA KEV: No
In EU EUVD: Yes (EUVD-2008-5530)
Published: December 12, 2008
NVD last modified: June 16, 2026
Status: Modified

EU Vulnerability Database (EUVD)

This vulnerability is also tracked by ENISA as EUVD-2008-5530 in the EU Vulnerability Database. Last updated in EUVD on August 7, 2024.

View on the EU Vulnerability Database

Affected products

microsoft / internet explorer

References

Last updated September 17, 2026 · Source: NVD, CISA KEV, FIRST.org EPSS

Query CVEs from your AI assistant

The CVE/NVD Explorer brain answers CVE questions directly inside Claude, ChatGPT, or any MCP assistant — always up to date, no setup. Add it once and stop pasting advisories into chat.

Add the CVE brain