How severe is CVE-2021-43841?

CVE-2021-43841 has a CVSS score of 5.4/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2021-43841?

CVE-2021-43841 affects the following packages: org.xwiki.platform:xwiki-platform-oldcore (Maven), org.xwiki.platform:xwiki-platform-oldcore (Maven), org.xwiki.platform:xwiki-platform-tool-configuration-resources (Maven), org.xwiki.platform:xwiki-platform-tool-configuration-resources (Maven). Ecosystems affected: Maven.

How do I fix CVE-2021-43841?

Update org.xwiki.platform:xwiki-platform-oldcore to 12.10.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-43841 is resolved across your whole dependency graph.

How do I detect CVE-2021-43841 in my Maven dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.xwiki.platform:xwiki-platform-oldcore, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2021-43841 if there is no patch (or I can't update yet)?

Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.

Is CVE-2021-43841 actively exploited in the wild?

Yes. There are 1 known exploit references for CVE-2021-43841, including 1 in-the-wild exploitation observed on GitHub and other sources. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for CVE-2021-43841?

CVE-2021-43841 has an EPSS (Exploit Prediction Scoring System) score of 0.9%, placing it in the 58th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2021-43841?

CVE-2021-43841 is classified as Cross-site Scripting (XSS) (CWE-79). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was CVE-2021-43841 published, and has it been updated?

CVE-2021-43841 was published on February 4, 2022 and was last updated on August 7, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

☕

☕ Maven

Not in CISA KEV

MEDIUM severity

CVE-2021-43841 — xwiki-platform-oldcore

MEDIUMFix: xwiki/xwiki-platform@5853d49

CVE-2021-43841 is a medium-severity (CVSS 5.4) Cross-site Scripting (XSS) vulnerability in org.xwiki.platform:xwiki-platform-oldcore. 1 public exploit reference exists, so weaponization risk is real. A fix is available for org.xwiki.platform:xwiki-platform-oldcore — see the affected versions and patch details below.

Cross-site Scripting by SVG upload in xwiki-platform

Also known asGHSA-9jq9-c2cv-pcrj

Published

Feb 4, 2022

Updated

Aug 7, 2026

Affected

4 pkgs

Patched

4 / 4

Exploits

1 known

Exploitation data as of Oct 7, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

Proof-of-concept exploit code exists

CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.

Exploitation and automatability from CISA’s SSVC triage for CVE-2021-43841.

EPSS Exploitation Probability

via FIRST.org ↗

0.9%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs58th percentile — riskier than 58% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

CVE-2021-43841 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.

Where this sits among everything scored

Of 385,738 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.

Real-World Exposure

4 pkgs affected

☕org.xwiki.platform:xwiki-platform-oldcore☕org.xwiki.platform:xwiki-platform-oldcore☕org.xwiki.platform:xwiki-platform-tool-configuration-resources☕org.xwiki.platform:xwiki-platform-tool-configuration-resources

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.

Description

Impact

When using default XWiki configuration, it's possible for an attacker to upload an SVG containing a script executed when executing the download action on the file.

Patches

This problem has been patched so that the default configuration doesn't allow to display the SVG files in the browser.

Workarounds

This issue can be fixed without the patch by setting properly the configuration to download or display files, see: https://www.xwiki.org/xwiki/bin/view/Documentation/AdminGuide/Attachments#HAttachmentdisplayordownload

References

https://jira.xwiki.org/browse/XWIKI-18368

For more information

If you have any questions or comments about this advisory:

Open an issue in Jira
Email us at security ML

Affected Packages

4 total 4 fixed

Ecosystem	Package	Vulnerable range	Fix
☕Maven	`org.xwiki.platform:xwiki-platform-oldcore`	all versions	12.10.6`org.xwiki.platform:xwiki-platform-oldcore:12.10.6`
☕Maven	`org.xwiki.platform:xwiki-platform-oldcore`	≥ 13.0&&< 13.3RC1	13.3RC1`org.xwiki.platform:xwiki-platform-oldcore:13.3RC1`
☕Maven	`org.xwiki.platform:xwiki-platform-tool-configuration-resources`	≥ 13.0&&< 13.3RC1	13.3RC1`org.xwiki.platform:xwiki-platform-tool-configuration-resources:13.3RC1`
☕Maven	`org.xwiki.platform:xwiki-platform-tool-configuration-resources`	all versions	12.10.6`org.xwiki.platform:xwiki-platform-tool-configuration-resources:12.10.6`

Affected Products

1 product · 2 configurations

Application

xwikixwiki

≥ 13.0 && ≤ 13.2

range

Exploits & PoCs

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

XWiki is a generic wiki platform offering runtime services for applicati…

jira.xwiki.orgNVDFeb 2022

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.xwiki.platform:xwiki-platform-oldcore, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update org.xwiki.platform:xwiki-platform-oldcore to 12.10.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-43841 is resolved across your whole dependency graph.
Workarounds
Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.

Frequently Asked Questions

### Impact When using default XWiki configuration, it's possible for an attacker to upload an SVG containing a script executed when executing the download action on the file. ### Patches This problem has been patched so that the default configuration doesn't allow to display the SVG files in the browser. ### Workarounds This issue can be fixed without the patch by setting properly the configuration to download or display files, see: https://www.xwiki.org/xwiki/bin/view/Documentation/AdminGuide/Attachments#HAttachmentdisplayordownload ### References https://jira.xwiki.org/browse/XWIKI-18368