CVE-2024-4027 | Undertow: outofmemoryerror in httpservletrequestimpl.getparameternames() can cause remote dos attacks

A flaw was found in Undertow. Servlets using a method that calls HttpServletRequestImpl.getParameterNames() can cause an OutOfMemoryError when the client sends a request with large parameter names. This issue can be exploited by an unauthorized user to cause a remote denial-of-service (DoS) attack.

Published: 2026-01-30 Last update: 2026-04-15 Assigner: [email protected] Source: [email protected]
NVD Status：Deferred，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2024-4027 is rated Moderate Risk (51/100): CVSS High severity, with medium exploitation likelihood (EPSS 0.38%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2024-4027

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-01 0.27% 0.38% +0.11%
2 2026-01-31 — 0.27% —

Full EPSS history (2 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2024-4027

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 [email protected]

Weakness enumeration for CVE-2024-4027

GitHub Security Advisory for CVE-2024-4027

GHSA-33hj-rcmx-86mv · Severity: high · Ecosystem: maven — Undertow Servlets Vulnerable to Remote DoS via OutOfMemoryError when Passed Large Parameter Names

OS Trackers for CVE-2024-4027

vendor priority summary link
debian not yet assigned CVE-2024-4027 not yet assigned priority: Debian including 1 source packages (undertow), 2 status rows across 2 suites (forky, sid): open 2. https://security-tracker.debian.org/tracker/CVE-2024-4027
redhat high — https://access.redhat.com/security/cve/CVE-2024-4027
ubuntu medium CVE-2024-4027 medium priority: Ubuntu including 1 source packages (undertow), 7 status rows across 7 suites (bionic, focal, jammy, noble, questing, upstream, xenial): needs-triage 7. https://ubuntu.com/security/CVE-2024-4027

Affected software / configurations for CVE-2024-4027

Vendor Product Version Raw CPE
No affected products in dataset.

References for CVE-2024-4027

cvelogic Threat Intelligence