How severe is CVE-2023-40176?

CVE-2023-40176 has a CVSS score of 9/10, rated CRITICAL. Immediate patching is strongly recommended.

Which packages are affected by CVE-2023-40176?

CVE-2023-40176 affects the following packages: org.xwiki.platform:xwiki-platform-web-templates (Maven). Ecosystems affected: Maven.

How do I fix CVE-2023-40176?

Update org.xwiki.platform:xwiki-platform-web-templates to 14.10.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-40176 is resolved across your whole dependency graph.

How do I detect CVE-2023-40176 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-web-templates, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2023-40176 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-2023-40176 actively exploited in the wild?

No public exploit code has been indexed for CVE-2023-40176 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2023-40176?

CVE-2023-40176 has an EPSS (Exploit Prediction Scoring System) score of 80.0%, placing it in the 100th 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. A score above 50% indicates significantly elevated exploitation risk — immediate patching is strongly recommended.

What type of vulnerability is CVE-2023-40176?

CVE-2023-40176 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-2023-40176 published, and has it been updated?

CVE-2023-40176 was published on August 23, 2023 and was last updated on October 28, 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

CRITICAL severity

CVE-2023-40176 — xwiki-platform-web-templa…

CRITICALFix: xwiki/xwiki-platform@d11ca5d

CVE-2023-40176 is a critical-severity (CVSS 9) Cross-site Scripting (XSS) vulnerability in org.xwiki.platform:xwiki-platform-web-templates. EPSS puts its 30-day exploitation probability at 80.0% (100th percentile). A fix is available for org.xwiki.platform:xwiki-platform-web-templates — see the affected versions and patch details below.

SXSS in the user profile via the timezone displayer

Also known asGHSA-h8cm-3v5f-rgp6

Published

Aug 23, 2023

Updated

Oct 28, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

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

Exploitation Status

No confirmed exploitation observed yet

A successful exploit gives an attacker total control of the affected component, not partial access.
CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2023-40176.

EPSS Exploitation Probability

via FIRST.org ↗

80.0%probability of exploitation in next 30 days

Very High Risk0.00%

Lower risk than most CVEs100th percentile — riskier than 100% of all scored CVEsHighest risk

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

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

1 pkg affected

☕org.xwiki.platform:xwiki-platform-web-templates

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

Any registered user can exploit a stored XSS through their user profile by setting the payload as the value of the time zone user preference. Even though the time zone is selected from a drop down (no free text value) it can still be set from JavaScript (using the browser developer tools) or by calling the save URL on the user profile with the right query string. Once the time zone is set it is displayed without escaping which means the payload gets executed for any user that visits the malicious user profile, allowing the attacker to steal information and even gain more access rights (escalation to programming rights).

The problem is present since version 4.1M2 when the time zone user preference was introduced.

Patches

The issue has been fixed in XWiki 14.10.5 and 15.1RC1 by https://github.com/xwiki/xwiki-platform/commit/d11ca5d781f8a42a85bc98eb82306c1431e764d4 . The main fix is in the displayer_timezone.vm precisely at this line:

$!escapetool.xml($value)

By escaping the displayed time zone value we make sure the attacker's payload is not executed.

Workarounds

If you want to fix this problem on older versions of XWiki that have not been patched then you need to edit displayer_timezone.vm and escape the displayed time zone value here:

- $!value
+ $!escapetool.xml($value)

References

For more information

If you have any questions or comments about this advisory:

Open an issue in Jira XWiki.org
Email us at Security Mailing List

Attribution

This vulnerability has been found and reported by @michitux .

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
☕Maven	`org.xwiki.platform:xwiki-platform-web-templates`	≥ 4.1-milestone-2&&< 14.10.5	14.10.5`org.xwiki.platform:xwiki-platform-web-templates:14.10.5`

Affected Products

1 product · 4 configurations

Application

xwikixwiki

≥ 4.1.1 && < 14.10.5

2 versions

4.115.0

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-web-templates, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update org.xwiki.platform:xwiki-platform-web-templates to 14.10.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-40176 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 Any registered user can exploit a stored XSS through their user profile by setting the payload as the value of the time zone user preference. Even though the time zone is selected from a drop down (no free text value) it can still be set from JavaScript (using the browser developer tools) or by calling the save URL on the user profile with the right query string. Once the time zone is set it is displayed without escaping which means the payload gets executed for any user that visits the malicious user profile, allowing the attacker to steal information and even gain more access rig