CVE-2021-43841Network attack vector

Stored XSS via inline SVG attachment rendering

Published Feb 4, 2022 · Updated Apr 22, 2025

Stored XSS in XWiki Platform before 12.10.6 and 13.0 through 13.3RC1 allows remote authenticated users to run script in a user's browser. DownloadAction includes image/svg+xml in its default inline-display MIME-type whitelist, so an uploaded script-bearing SVG is served for browser rendering. An attacker needs attachment-upload permission and a user must invoke the download action; the script then runs in the XWiki origin and can access session-visible data.

CVSS severity4.1
Medium
EPSS probability0.87%
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 XWiki Platform before 12.10.6 and 13.0 through 13.3RC1 allows remote authenticated users to run script in a user's browser. DownloadAction includes image/svg+xml in its default inline-display MIME-type whitelist, so an uploaded script-bearing SVG is served for browser rendering. An attacker needs attachment-upload permission and a user must invoke the download action; the script then runs in the XWiki origin and can access session-visible data.

The record

CVE
CVE-2021-43841
Published
Feb 4, 2022
Updated
Apr 22, 2025
Vendor
CryptPad
Product
XWiki Platform
Classifications
CWE-184, CWE-79, T1189
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 4, 2022CVE publishedPublication date reported by the CVE source.
  2. Apr 22, 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=< 12.10.6
  2. Affected versionversion=>= 13.0, < 13.3RC1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

CryptPad · XWiki Platformversion=< 12.10.6; version=>= 13.0, < 13.3RC1

Published CVSS scores

4.1GitHubCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:N/A:N
5.4NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
3.5NIST NVDAV:N/AC:M/Au:S/C:N/I:P/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-184Incomplete List of Disallowed Inputs
CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1189Drive-by Compromise

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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