CVE-2021-26087Network attack vector

Stored script execution via GUI payload injection

Published Mar 17, 2025 · Updated Mar 17, 2025

Stored XSS in the Fortinet FortiWLC web interface allows attackers to execute scripts in users' browsers via injected payloads. Fortinet identifies the GUI as the affected component but has not disclosed the input fields or output-encoding failure that stores and renders the payload. Exploitation requires authenticated remote access or unauthenticated access from the appliance's local network, and execution occurs when a user views the poisoned interface content.

CVSS severity6.1
Medium
EPSS probability0.33%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stored XSS in the Fortinet FortiWLC web interface allows attackers to execute scripts in users' browsers via injected payloads. Fortinet identifies the GUI as the affected component but has not disclosed the input fields or output-encoding failure that stores and renders the payload. Exploitation requires authenticated remote access or unauthenticated access from the appliance's local network, and execution occurs when a user views the poisoned interface content.

The record

CVE
CVE-2021-26087
Published
Mar 17, 2025
Updated
Mar 17, 2025
Vendor
Fortinet
Product
FortiWLC
Classifications
CWE-79, T1059.007
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 17, 2025CVE publishedPublication date reported by the CVE source.
  2. Mar 17, 2025Record 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=8.3.3
  2. Affected versionversion=8.4.0 <=8.4.2
  3. Affected versionversion=8.4.4 <=8.4.8
  4. Affected versionversion=8.5.0 <=8.5.3
  5. Affected versionversion=8.6.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Fortinet · FortiWLCversion=8.3.3; version=8.4.0 <=8.4.2; version=8.4.4 <=8.4.8; version=8.5.0 <=8.5.3; version=8.6.0

Published CVSS scores

6.1NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1059.007JavaScript/JScript

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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