How severe is CVE-2011-4858?

No CVSS score has been assigned to CVE-2011-4858 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2011-4858?

CVE-2011-4858 affects the following packages: org.apache.tomcat:tomcat (Maven), org.apache.tomcat:tomcat (Maven), org.apache.tomcat:tomcat (Maven). Ecosystems affected: Maven.

How do I fix CVE-2011-4858?

Update org.apache.tomcat:tomcat to 5.5.35 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2011-4858 is resolved across your whole dependency graph.

How do I detect CVE-2011-4858 in my Maven dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.apache.tomcat:tomcat, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2011-4858 if there is no patch (or I can't update yet)?

Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.

Is CVE-2011-4858 actively exploited in the wild?

Yes. There are 2 known exploit references for CVE-2011-4858, including 1 documented proof-of-concept exploit on Exploit-DB and 1 in-the-wild exploitation observed on GitHub and other sources. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for CVE-2011-4858?

CVE-2011-4858 has an EPSS (Exploit Prediction Scoring System) score of 79.7%, placing it in the 100th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. A score above 50% indicates significantly elevated exploitation risk — immediate patching is strongly recommended.

What type of vulnerability is CVE-2011-4858?

CVE-2011-4858 is classified as CWE-399 (CWE-399). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2011-4858 published, and has it been updated?

CVE-2011-4858 was published on May 14, 2022 and was last updated on November 8, 2023. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

☕ Maven

Not in CISA KEV

CVE-2011-4858 — tomcat

CVE-2011-4858 is a CWE-399 vulnerability in org.apache.tomcat:tomcat. 2 public exploit or proof-of-concept references are indexed, so weaponization risk is real. A fix is available for org.apache.tomcat:tomcat — see the affected versions and patch details below.

Improper Input Validation in Apache Tomcat

Published

May 14, 2022

Updated

Nov 8, 2023

Affected

3 pkgs

Patched

3 / 3

Exploits

2 known

Exploitation data as of Nov 1, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

79.7%probability of exploitation in next 30 days

Very High Risk0.00%

Lower risk than most CVEs100th percentile — riskier than 100% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Real-World Exposure

3 pkgs affected

☕org.apache.tomcat:tomcat☕org.apache.tomcat:tomcat☕org.apache.tomcat:tomcat

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.

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.

Affected Packages

3 total 3 fixed

Ecosystem	Package	Vulnerable range	Fix
☕Maven	`org.apache.tomcat:tomcat`	≥ 5.5.0&&< 5.5.35	5.5.35`org.apache.tomcat:tomcat:5.5.35`
☕Maven	`org.apache.tomcat:tomcat`	≥ 6.0.0&&< 6.0.35	6.0.35`org.apache.tomcat:tomcat:6.0.35`
☕Maven	`org.apache.tomcat:tomcat`	≥ 7.0.0&&< 7.0.23	7.0.23`org.apache.tomcat:tomcat:7.0.23`

Affected Products

1 product · 59 configurations

Application

tomcatapache

59 versions

5.5.356.0.06.0.16.0.26.0.36.0.46.0.56.0.66.0.76.0.86.0.96.0.10

Exploits & PoCs

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

EDB-2012webappsphp✓ Verified

MyBulletinBoard (MyBB) 1.1.5 - 'CLIENT-IP' SQL Injection

by rgod · Jul 15, 2006

Exploit-DB Source

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.apache.tomcat:tomcat, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update org.apache.tomcat:tomcat to 5.5.35 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2011-4858 is resolved across your whole dependency graph.
Workarounds
Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.

Fixing This On Your OS

If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.

Red HatModerate

Product	Fixed in	Advisory
JBEWP 5 for RHEL 5	`jbossweb-0:2.1.12-3_patch_03.2.ep5.el5`	RHSA-2012:0076
JBoss Communications Platform 5.1	see advisory	RHSA-2012:0078
JBoss Enterprise BRMS Platform 5.1	see advisory	RHSA-2012:0325
Red Hat Enterprise Linux 5	`tomcat5-0:5.5.23-0jpp.31.el5_8`	RHSA-2012:0474
Red Hat Enterprise Linux 6	`tomcat6-0:6.0.24-36.el6_2`	RHSA-2012:0475
Red Hat JBoss Enterprise Application Platform 4.3	see advisory	RHSA-2012:0041
Red Hat JBoss Enterprise Application Platform 5.1	see advisory	RHSA-2012:0075
Red Hat JBoss Enterprise Application Platform 5 for RHEL 5	`jbossweb-0:2.1.12-3_patch_03.2.ep5.el5`	RHSA-2012:0074

Ubuntu

USN-1359-1Ubuntu

Frequently Asked Questions

O3 Security · Impact-Aware SCA

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