How severe is CVE-2011-1475?

CVE-2011-1475 has a CVSS 2.0 base score of 5.0, rated medium severity.

Is CVE-2011-1475 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 9% (94th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2011-1475?

CVE-2011-1475 primarily affects Apache Tomcat. In total, 13 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2011-1475?

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

When was CVE-2011-1475 published?

CVE-2011-1475 was published on 2011-04-08 and last updated on 2026-06-16.

CVE-2011-1475

CVE-2011-1475 is a medium-severity vulnerability in Apache Tomcat with a CVSS 2.0 base score of 5.0. 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-20.

Key facts

Severity: Medium (CVSS 2.0 base score 5.0)
EPSS exploit prediction: 9% (94th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-20
Affected product: Apache Tomcat
Published: 2011-04-08
Last modified: 2026-06-16

Description

The HTTP BIO connector in Apache Tomcat 7.0.x before 7.0.12 does not properly handle HTTP pipelining, which allows remote attackers to read responses intended for other clients in opportunistic circumstances by examining the application data in HTTP packets, related to "a mix-up of responses for requests from different users."

Frequently asked questions

What is CVE-2011-1475?: The HTTP BIO connector in Apache Tomcat 7.0.x before 7.0.12 does not properly handle HTTP pipelining, which allows remote attackers to read responses intended for other clients in opportunistic circumstances by examining the application data in HTTP packets, related to "a mix-up of responses for requests from different users."
How severe is CVE-2011-1475?: CVE-2011-1475 has a CVSS 2.0 base score of 5.0, rated medium severity.
Is CVE-2011-1475 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 9% (94th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2011-1475?: CVE-2011-1475 primarily affects Apache Tomcat. In total, 13 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2011-1475?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2011-1475 published?: CVE-2011-1475 was published on 2011-04-08 and last updated on 2026-06-16.

References

Affected products (13)

cpe:2.3:a:apache:tomcat:7.0.0:*:*:*:*:*:*:*
cpe:2.3:a:apache:tomcat:7.0.0:beta:*:*:*:*:*:*
cpe:2.3:a:apache:tomcat:7.0.1:*:*:*:*:*:*:*
cpe:2.3:a:apache:tomcat:7.0.2:*:*:*:*:*:*:*
cpe:2.3:a:apache:tomcat:7.0.3:*:*:*:*:*:*:*
cpe:2.3:a:apache:tomcat:7.0.4:*:*:*:*:*:*:*
cpe:2.3:a:apache:tomcat:7.0.5:*:*:*:*:*:*:*
cpe:2.3:a:apache:tomcat:7.0.6:*:*:*:*:*:*:*
cpe:2.3:a:apache:tomcat:7.0.7:*:*:*:*:*:*:*
cpe:2.3:a:apache:tomcat:7.0.8:*:*:*:*:*:*:*
cpe:2.3:a:apache:tomcat:7.0.9:*:*:*:*:*:*:*
cpe:2.3:a:apache:tomcat:7.0.10:*:*:*:*:*:*:*
cpe:2.3:a:apache:tomcat:7.0.11:*:*:*:*:*:*:*

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