Is CVE-2009-2621 in the CISA KEV catalog?

No. CVE-2009-2621 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2009-2621?

CVE-2009-2621 has a CVSS v2 base score of 5.0 (MEDIUM).

What is the EPSS score for CVE-2009-2621?

CVE-2009-2621 has an EPSS score of 23.05% (97th percentile), estimating the probability of exploitation in the next 30 days.

CVE & CISA-KEV Catalog

CVE-2009-2621

MEDIUMEPSS 97th pctl

5.0

CVSS v2

NVD

Description

Squid 3.0 through 3.0.STABLE16 and 3.1 through 3.1.0.11 does not properly enforce "buffer limits and related bound checks," which allows remote attackers to cause a denial of service via (1) an incomplete request or (2) a request with a large header size, related to (a) HttpMsg.cc and (b) client_side.cc.

CWE-119Buffer Overflow

CVSS v2 Vector

No CVSS vector data available.

Exploit Intelligence

23.05%probability of exploitation in 30 days

97thpercentile

Very high risk: more likely to be exploited than 97% 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.