CVE-2023-51447Network attack vector

Stored XSS via unescaped upload filenames

Published Feb 20, 2024 · Updated Aug 26, 2024

Stored XSS in Decidim 0.27.0 through 0.27.4 allows remote authenticated users to execute script via a crafted upload filename. Dynamic upload modals insert Active Storage blob filenames into innerHTML without HTML escaping, causing filename markup to become executable DOM content. Exploitation requires a crafted direct-upload request, manual blob attachment to a record, and another user opening that record's edit page.

CVSS severity6.3
Medium
EPSS probability0.49%
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 Decidim 0.27.0 through 0.27.4 allows remote authenticated users to execute script via a crafted upload filename. Dynamic upload modals insert Active Storage blob filenames into innerHTML without HTML escaping, causing filename markup to become executable DOM content. Exploitation requires a crafted direct-upload request, manual blob attachment to a record, and another user opening that record's edit page.

The record

CVE
CVE-2023-51447
Published
Feb 20, 2024
Updated
Aug 26, 2024
Vendor
Decidim
Product
Decidim
Classifications
CWE-79, T1203
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 20, 2024CVE publishedPublication date reported by the CVE source.
  2. Aug 26, 2024Record 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=>= 0.27.0, < 0.27.5
  2. Affected versionversion=0.27.0 <0.27.5

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Decidim · Decidimversion=>= 0.27.0, < 0.27.5; version=0.27.0 <0.27.5

Published CVSS scores

5.4NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
6.3GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/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
Privilegesauthenticated
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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