CVE-2021-41118Network attack vector

Service hang via unsanitized date regex

Published Oct 4, 2021 · Updated Aug 4, 2024

Regular expression denial of service in DynamicPageList3 before 3.3.6 allows remote attackers to hang MediaWiki via crafted DPL input. The DPL parser evaluates an unsanitized date regular expression supplied through parser-function parameters, allowing excessive processing to exhaust service capacity. Exploitation requires the crafted parser call to be rendered, and the documented consequence is loss of availability rather than data access or modification.

CVSS severity5.3
Medium
EPSS probability1.16%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Regular expression denial of service in DynamicPageList3 before 3.3.6 allows remote attackers to hang MediaWiki via crafted DPL input. The DPL parser evaluates an unsanitized date regular expression supplied through parser-function parameters, allowing excessive processing to exhaust service capacity. Exploitation requires the crafted parser call to be rendered, and the documented consequence is loss of availability rather than data access or modification.

The record

CVE
CVE-2021-41118
Published
Oct 4, 2021
Updated
Aug 4, 2024
Vendor
Universal Omega
Product
DynamicPageList3
Classifications
CWE-400, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Oct 4, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 3.3.6

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Universal Omega · DynamicPageList3version=< 3.3.6

Published CVSS scores

7.5NISTCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
5.0NISTAV:N/AC:L/Au:N/C:N/I:N/A:P
5.3GitHub, Inc.CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-400Uncontrolled Resource Consumption
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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