Is CVE-2008-5556 in the CISA KEV catalog?

No. CVE-2008-5556 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2008-5556?

CVE-2008-5556 has a CVSS v2 base score of 4.3 (MEDIUM).

What is the EPSS score for CVE-2008-5556?

CVE-2008-5556 has an EPSS score of 11.22% (95th percentile), estimating the probability of exploitation in the next 30 days.

CVE & CISA-KEV Catalog

CVE-2008-5556

MEDIUMEPSS 95th pctl

4.3

CVSS v2

NVD

Description

The XSS Filter in Microsoft Internet Explorer 8.0 Beta 2 does not recognize attack patterns designed to operate against web pages that are encoded with utf-7, which allows remote attackers to bypass the XSS protection mechanism and conduct XSS attacks by injecting crafted utf-7 content. NOTE: the vendor reportedly disputes this issue, stating "Behaviour is by design.

CWE-79Cross-Site Scripting (XSS)

CVSS v2 Vector

No CVSS vector data available.

Exploit Intelligence

11.22%probability of exploitation in 30 days

95thpercentile

Very high risk: more likely to be exploited than 95% of all known CVEs.

References

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-04-23.