CVE-2021-21080Network attack vector

Browser JavaScript execution via reflected query parameter

Published Mar 12, 2021 · Updated Apr 23, 2025

Reflected XSS in Adobe Connect 11.0.7 and earlier allows remote attackers to run JavaScript in a victim's browser via a query parameter. The published records identify a query parameter as the injection vector but do not disclose the parameter, request handler, or failed output-encoding operation. A victim must browse to a page containing the crafted field; successful execution can read or alter data available to that page's browser context.

CVSS severity6.1
Medium
EPSS probability1.19%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Reflected XSS in Adobe Connect 11.0.7 and earlier allows remote attackers to run JavaScript in a victim's browser via a query parameter. The published records identify a query parameter as the injection vector but do not disclose the parameter, request handler, or failed output-encoding operation. A victim must browse to a page containing the crafted field; successful execution can read or alter data available to that page's browser context.

The record

CVE
CVE-2021-21080
Published
Mar 12, 2021
Updated
Apr 23, 2025
Vendor
Adobe
Product
Adobe Connect
Classifications
CWE-79, T1189
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 12, 2021CVE publishedPublication date reported by the CVE source.
  2. Apr 23, 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=unspecified <=11.0.7
  2. Affected versionversion=unspecified <=None

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Adobe · Adobe Connectversion=unspecified <=11.0.7; version=unspecified <=None

Published CVSS scores

6.1Adobe Systems IncorporatedCVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
6.1NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
4.3NIST NVDAV:N/AC:M/Au:N/C:N/I:P/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')
T1189Drive-by Compromise

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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