How severe is CVE-2009-2622?

CVE-2009-2622 has a CVSS 2.0 base score of 5.0, rated medium severity.

Is CVE-2009-2622 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 57% (99th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2009-2622?

CVE-2009-2622 primarily affects Squid-cache Squid. In total, 29 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2009-2622?

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

When was CVE-2009-2622 published?

CVE-2009-2622 was published on 2009-07-28 and last updated on 2026-06-16.

CVE-2009-2622

CVE-2009-2622 is a medium-severity vulnerability in Squid-cache Squid with a CVSS 2.0 base score of 5.0. Its EPSS exploit-prediction score of 57% places it in the 99th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-20.

Key facts

Severity: Medium (CVSS 2.0 base score 5.0)
EPSS exploit prediction: 57% (99th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-20
Affected product: Squid-cache Squid
Published: 2009-07-28
Last modified: 2026-06-16

Description

Squid 3.0 through 3.0.STABLE16 and 3.1 through 3.1.0.11 allows remote attackers to cause a denial of service via malformed requests including (1) "missing or mismatched protocol identifier," (2) missing or negative status value," (3) "missing version," or (4) "missing or invalid status number," related to (a) HttpMsg.cc and (b) HttpReply.cc.

Frequently asked questions

What is CVE-2009-2622?: Squid 3.0 through 3.0.STABLE16 and 3.1 through 3.1.0.11 allows remote attackers to cause a denial of service via malformed requests including (1) "missing or mismatched protocol identifier," (2) missing or negative status value," (3) "missing version," or (4) "missing or invalid status number," related to (a) HttpMsg.cc and (b) HttpReply.cc.
How severe is CVE-2009-2622?: CVE-2009-2622 has a CVSS 2.0 base score of 5.0, rated medium severity.
Is CVE-2009-2622 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 57% (99th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2009-2622?: CVE-2009-2622 primarily affects Squid-cache Squid. In total, 29 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2009-2622?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2009-2622 published?: CVE-2009-2622 was published on 2009-07-28 and last updated on 2026-06-16.

References

Affected products (29)

cpe:2.3:a:squid-cache:squid:3.0:*:pre1:*:*:*:*:*
cpe:2.3:a:squid-cache:squid:3.0:*:pre2:*:*:*:*:*
cpe:2.3:a:squid-cache:squid:3.0:*:pre3:*:*:*:*:*
cpe:2.3:a:squid-cache:squid:3.0:*:pre4:*:*:*:*:*
cpe:2.3:a:squid-cache:squid:3.0:*:pre5:*:*:*:*:*
cpe:2.3:a:squid-cache:squid:3.0:*:pre6:*:*:*:*:*
cpe:2.3:a:squid-cache:squid:3.0:*:pre7:*:*:*:*:*
cpe:2.3:a:squid-cache:squid:3.0:*:stable1:*:*:*:*:*
cpe:2.3:a:squid-cache:squid:3.0:*:stable10:*:*:*:*:*
cpe:2.3:a:squid-cache:squid:3.0:*:stable11:*:*:*:*:*
cpe:2.3:a:squid-cache:squid:3.0:*:stable12:*:*:*:*:*
cpe:2.3:a:squid-cache:squid:3.0:*:stable13:*:*:*:*:*
cpe:2.3:a:squid-cache:squid:3.0:*:stable14:*:*:*:*:*
cpe:2.3:a:squid-cache:squid:3.0:*:stable15:*:*:*:*:*
cpe:2.3:a:squid-cache:squid:3.0:*:stable2:*:*:*:*:*
cpe:2.3:a:squid-cache:squid:3.0:*:stable3:*:*:*:*:*
cpe:2.3:a:squid-cache:squid:3.0:*:stable4:*:*:*:*:*
cpe:2.3:a:squid-cache:squid:3.0:*:stable5:*:*:*:*:*
cpe:2.3:a:squid-cache:squid:3.0:*:stable6:*:*:*:*:*
cpe:2.3:a:squid-cache:squid:3.0:*:stable7:*:*:*:*:*
cpe:2.3:a:squid-cache:squid:3.0:*:stable8:*:*:*:*:*
cpe:2.3:a:squid-cache:squid:3.0:*:stable9:*:*:*:*:*
cpe:2.3:a:squid-cache:squid:3.0:rc1:stable11:*:*:*:*:*
cpe:2.3:a:squid-cache:squid:3.0:rc4:*:*:*:*:*:*
cpe:2.3:a:squid-cache:squid:3.1:*:*:*:*:*:*:*
cpe:2.3:a:squid-cache:squid:3.1.0.1:*:*:*:*:*:*:*
cpe:2.3:a:squid-cache:squid:3.1.0.2:*:*:*:*:*:*:*
cpe:2.3:a:squid-cache:squid:3.1.0.3:*:*:*:*:*:*:*
cpe:2.3:a:squid-cache:squid:3.1.0.4:*:*:*:*:*:*:*

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