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
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
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2023-40176 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE sits: patch-first territory.
Where this sits among everything scored
Of 378,156 CVEs with a current EPSS score, this one falls in the 50–90% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
org.xwiki.platform:xwiki-platform-web-templatesReal-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
- JIRA issue https://jira.xwiki.org/browse/XWIKI-20276
- Fix https://github.com/xwiki/xwiki-platform/commit/d11ca5d781f8a42a85bc98eb82306c1431e764d4
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
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | org.xwiki.platform:xwiki-platform-web-templates | ≥ 4.1-milestone-2&&< 14.10.5 | 14.10.5org.xwiki.platform:xwiki-platform-web-templates:14.10.5 |
Detection & mitigation playbook
Open-source dependencyDetect
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
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2023-40176 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2023-40176. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2023-40176 in your dependencies?
O3 Security finds CVE-2023-40176 across Maven dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.