CVE-2026-21664Network attack vector

Administrator browser script execution via unescaped target parameter

Published Jan 20, 2026 · Updated Jan 20, 2026

Reflected XSS in Revive Adserver 6.0.4 and earlier allows remote attackers to execute script in an administrator's browser via a crafted URL. The afr.php delivery script passes the target GET parameter into MAX_adSelect, which places it unescaped in an HTML anchor target attribute. Execution requires a logged-in administrator to visit the URL; resulting access depends on configuration locking and separation of the admin and delivery domains.

CVSS severity6.1
Medium
EPSS probability0.17%
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 Revive Adserver 6.0.4 and earlier allows remote attackers to execute script in an administrator's browser via a crafted URL. The afr.php delivery script passes the target GET parameter into MAX_adSelect, which places it unescaped in an HTML anchor target attribute. Execution requires a logged-in administrator to visit the URL; resulting access depends on configuration locking and separation of the admin and delivery domains.

The record

CVE
CVE-2026-21664
Published
Jan 20, 2026
Updated
Jan 20, 2026
Vendor
Revive Adserver Project
Product
Revive Adserver
Classifications
CWE-79, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 20, 2026CVE publishedPublication date reported by the CVE source.
  2. Jan 20, 2026Record 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=6 <=6.0.4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Revive Adserver Project · Revive Adserverversion=6 <=6.0.4

Published CVSS scores

6.1HackerOneCVSS:3.0/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 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')
T1203Exploitation for Client Execution

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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