CVE-2025-46595Network attack vector

Stored XSS via unverified flag-link response handling

Published Apr 25, 2025 · Updated Apr 25, 2025

Stored XSS in Backdrop CMS Flag before 1.x-3.6.2 allows remote authenticated users to execute script through crafted flag-link HTML. The module performs flag actions without validating the submitted link and accepts responses that are not verified as originating from Flag. The attacker must hold a role permitted to create links in filtered content or comments, exposing site visitors to attacker-supplied script in the site's origin.

CVSS severity6.4
Medium
EPSS probability0.23%
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 Backdrop CMS Flag before 1.x-3.6.2 allows remote authenticated users to execute script through crafted flag-link HTML. The module performs flag actions without validating the submitted link and accepts responses that are not verified as originating from Flag. The attacker must hold a role permitted to create links in filtered content or comments, exposing site visitors to attacker-supplied script in the site's origin.

The record

CVE
CVE-2025-46595
Published
Apr 25, 2025
Updated
Apr 25, 2025
Vendor
Backdrop CMS
Product
Flag
Classifications
CWE-79, T1190
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 25, 2025CVE publishedPublication date reported by the CVE source.
  2. Apr 25, 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=0 <1.x-3.6.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Backdrop CMS · Flagversion=0 <1.x-3.6.2

Published CVSS scores

6.4MITRECVSS:3.1/AV:N/AC:L/PR:L/UI:N/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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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