CVE-2011-4858

CVE-2011-4858 is a medium-severity vulnerability in Apache Tomcat with a CVSS 2.0 base score of 5.0. Its EPSS exploit-prediction score of 80% places it in the 100th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-399.

Key facts

Description

Apache Tomcat before 5.5.35, 6.x before 6.0.35, and 7.x before 7.0.23 computes hash values for form parameters without restricting the ability to trigger hash collisions predictably, which allows remote attackers to cause a denial of service (CPU consumption) by sending many crafted parameters.

Frequently asked questions

What is CVE-2011-4858?
Apache Tomcat before 5.5.35, 6.x before 6.0.35, and 7.x before 7.0.23 computes hash values for form parameters without restricting the ability to trigger hash collisions predictably, which allows remote attackers to cause a denial of service (CPU consumption) by sending many crafted parameters.
How severe is CVE-2011-4858?
CVE-2011-4858 has a CVSS 2.0 base score of 5.0, rated medium severity.
Is CVE-2011-4858 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 80% (100th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2011-4858?
CVE-2011-4858 primarily affects Apache Tomcat. In total, 59 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2011-4858?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2011-4858 published?
CVE-2011-4858 was published on 2012-01-05 and last updated on 2026-06-16.

References

Affected products (59)

More vulnerabilities in Apache Tomcat

All CVEs affecting Apache Tomcat →

Other CWE-399 (Resource Management Errors) vulnerabilities

Browse all CWE-399 (Resource Management Errors) vulnerabilities →