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CVE-2021-40539Zoho ManageEngine ADSelfService Plus Authentication Bypass Vulnerability

Zoho ManageEngine ADSelfService Plus version 6113 and prior is vulnerable to REST API authentication bypass with resultant remote code execution.

9.8 CRITICALEPSS 98.96%⚡ Known Exploited (CISA KEV)NVD: Analyzed

Last updated: 2026-06-17 04:07 UTC

OverviewCVSS details

9.8CRITICALCVSS 3.1

Score source: NVD
NVD status: Analyzed
Published: Sep 7, 2021
Assigner: mitre

Affected

manageengine adselfservice plus (zohocorp)

Versions: before 6.1 · 6.1
Fixed in: 6.1

All affected versions →

Exploitation

Public exploit: Yes · 1 reference
CISA KEV: Listed · Nov 3, 2021
KEV due date: Nov 17, 2021
Ransomware use: Known
SSVC: Exploitation active · Automatable yes · Impact total

EPSS · FIRST, scored Nov 7

98.96%chance of exploitation in 30 days

Higher than 99.92% of CVEs

CVSS 3.1 · NVD

9.8Critical

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Attack vector: Network
Attack complexity: Low
Privileges required: None
User interaction: None
Scope: Unchanged
Confidentiality impact: High
Integrity impact: High
Availability impact: High

CVSS 2.0 · NVD

7.5High

AV:N/AC:L/Au:N/C:P/I:P/A:P

Attack vector: Network
Attack complexity: Low
Authentication: None
Confidentiality impact: Partial
Integrity impact: Partial
Availability impact: Partial

NVD status: Analyzed

Overview Affected Products References

Overview

Severity

Score	Severity	Version	Vector String
9.8	CRITICAL	3.1NVD	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
7.5	HIGH	2.0NVD	AV:N/AC:L/Au:N/C:P/I:P/A:P

CISA required action

⚡ Known exploited · remediation due Nov 17, 2021

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Details

CVE ID: CVE-2021-40539
Status: Analyzed
Assigner (CNA): mitre
Published: Sep 7, 2021
Last modified: 2026-06-17 04:07 UTC
Weaknesses: CWE-706
CWE-55

Sources

Refreshed hourly from the sources above. Last fetched 2026-11-08 10:57 UTC.