CVE-2025-31806Network attack vector

Administrator stored XSS via unescaped saved input

Published Apr 1, 2025 · Updated May 11, 2026

Stored XSS in uSystems GmbH Webling 3.9.0 and earlier allows remote authenticated users to execute scripts through saved plugin input. The plugin stores administrator-supplied content without sufficient sanitization and later renders it without adequate output escaping; public advisories do not identify the affected parameter or code path. Administrator access plus a multisite installation or disabled unfiltered_html capability is required, and another user must view the injected content for script execution in that browser.

CVSS severity5.9
Medium
EPSS probability0.36%
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 uSystems GmbH Webling 3.9.0 and earlier allows remote authenticated users to execute scripts through saved plugin input. The plugin stores administrator-supplied content without sufficient sanitization and later renders it without adequate output escaping; public advisories do not identify the affected parameter or code path. Administrator access plus a multisite installation or disabled unfiltered_html capability is required, and another user must view the injected content for script execution in that browser.

The record

CVE
CVE-2025-31806
Published
Apr 1, 2025
Updated
May 11, 2026
Vendor
uSystems GmbH
Product
Webling
Classifications
CWE-79, CAPEC-592, T1203
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Apr 1, 2025CVE publishedPublication date reported by the CVE source.
  2. May 11, 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=0 <=3.9.0 changes=[{"at":"3.9.1","status":"unaffected"}]

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

uSystems GmbH · Weblingversion=0 <=3.9.0 changes=[{"at":"3.9.1","status":"unaffected"}]

Published CVSS scores

5.9PatchstackCVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:L

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')
CAPEC-592Stored XSS
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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