CVE-2025-20204Network attack vector

Stored XSS via insufficient guest portal validation

Published Feb 5, 2025 · Updated Jul 21, 2026

Stored XSS in Cisco Identity Services Engine 3.4 and earlier allows remote authenticated users to execute scripts in guest portals. The web management interface insufficiently validates administrative input before storing it in specific guest-portal pages, so a visitor's browser executes the injected code. Valid administrative credentials and victim interaction are required; execution occurs in the interface context and exposes sensitive browser-based information.

CVSS severity4.8
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 Cisco Identity Services Engine 3.4 and earlier allows remote authenticated users to execute scripts in guest portals. The web management interface insufficiently validates administrative input before storing it in specific guest-portal pages, so a visitor's browser executes the injected code. Valid administrative credentials and victim interaction are required; execution occurs in the interface context and exposes sensitive browser-based information.

The record

CVE
CVE-2025-20204
Published
Feb 5, 2025
Updated
Jul 21, 2026
Vendor
ClamAV
Product
Cisco Identity Services Engine
Classifications
CWE-79, T1203
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Feb 5, 2025CVE publishedPublication date reported by the CVE source.
  2. Jul 21, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=3.1.0
  2. Affected versionversion=3.1.0 p1
  3. Affected versionversion=3.1.0 p10
  4. Affected versionversion=3.1.0 p11
  5. Affected versionversion=3.1.0 p2
  6. Affected versionversion=3.1.0 p3
  7. Affected versionversion=3.1.0 p4
  8. Affected versionversion=3.1.0 p5
  9. Affected versionversion=3.1.0 p6
  10. Affected versionversion=3.1.0 p7
  11. Affected versionversion=3.1.0 p8
  12. Affected versionversion=3.1.0 p9
  13. Affected versionversion=3.2.0
  14. Affected versionversion=3.2.0 p1
  15. Affected versionversion=3.2.0 p2
  16. Affected versionversion=3.2.0 p3
  17. Affected versionversion=3.2.0 p4
  18. Affected versionversion=3.2.0 p5
  19. Affected versionversion=3.2.0 p6
  20. Affected versionversion=3.2.0 p7
  21. Affected versionversion=3.2 Patch 10
  22. Affected versionversion=3.2 Patch 8
  23. Affected versionversion=3.2 Patch 9
  24. Affected versionversion=3.3.0
  25. Affected versionversion=3.3 Patch 1
  26. Affected versionversion=3.3 Patch 10
  27. Affected versionversion=3.3 Patch 11
  28. Affected versionversion=3.3 Patch 2
  29. Affected versionversion=3.3 Patch 3
  30. Affected versionversion=3.3 Patch 4
  31. Affected versionversion=3.3 Patch 5
  32. Affected versionversion=3.3 Patch 6
  33. Affected versionversion=3.3 Patch 7
  34. Affected versionversion=3.3 Patch 8
  35. Affected versionversion=3.3 Patch 9
  36. Affected versionversion=3.4.0
  37. Affected versionversion=3.4 Patch 1
  38. Affected versionversion=3.4 Patch 2
  39. Affected versionversion=3.4 Patch 3
  40. Affected versionversion=3.4 Patch 4
  41. Affected versionversion=3.4 Patch 5
  42. Affected versionversion=3.4 Patch 6
  43. Affected versionversion=3.5.0
  44. Affected versionversion=3.5 Patch 1
  45. Affected versionversion=3.5 Patch 2
  46. Affected versionversion=3.5 Patch 3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

ClamAV · Cisco Identity Services Engineversion=3.1.0; version=3.1.0 p1; version=3.1.0 p10; version=3.1.0 p11; version=3.1.0 p2; version=3.1.0 p3; version=3.1.0 p4; version=3.1.0 p5; version=3.1.0 p6; version=3.1.0 p7; version=3.1.0 p8; version=3.1.0 p9; version=3.2.0; version=3.2.0 p1; version=3.2.0 p2; version=3.2.0 p3; version=3.2.0 p4; version=3.2.0 p5; version=3.2.0 p6; version=3.2.0 p7; version=3.2 Patch 10; version=3.2 Patch 8; version=3.2 Patch 9; version=3.3.0; version=3.3 Patch 1; version=3.3 Patch 10; version=3.3 Patch 11; version=3.3 Patch 2; version=3.3 Patch 3; version=3.3 Patch 4; version=3.3 Patch 5; version=3.3 Patch 6; version=3.3 Patch 7; version=3.3 Patch 8; version=3.3 Patch 9; version=3.4.0; version=3.4 Patch 1; version=3.4 Patch 2; version=3.4 Patch 3; version=3.4 Patch 4; version=3.4 Patch 5; version=3.4 Patch 6; version=3.5.0; version=3.5 Patch 1; version=3.5 Patch 2; version=3.5 Patch 3

Published CVSS scores

4.8CiscoCVSS:3.1/AV:N/AC:L/PR:H/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
Privilegesadmin
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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