How severe is CVE-2023-26477?

CVE-2023-26477 has a CVSS score of 10/10, rated CRITICAL. Immediate patching is strongly recommended.

Which packages are affected by CVE-2023-26477?

CVE-2023-26477 affects the following packages: org.xwiki.platform:xwiki-platform-flamingo-theme-ui (Maven), org.xwiki.platform:xwiki-platform-flamingo-theme-ui (Maven), org.xwiki.platform:xwiki-platform-flamingo-theme-ui (Maven). Ecosystems affected: Maven.

How do I fix CVE-2023-26477?

Update org.xwiki.platform:xwiki-platform-flamingo-theme-ui to 13.10.10 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-26477 is resolved across your whole dependency graph.

How do I detect CVE-2023-26477 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-flamingo-theme-ui, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2023-26477 if there is no patch (or I can't update yet)?

Stop passing untrusted input into the interpreter or shell: call the affected binary with an argument array rather than a composed command string, reject anything outside a strict allowlist of expected values, and run the component under an account that cannot reach beyond the work it legitimately does.

Is CVE-2023-26477 actively exploited in the wild?

Yes. There are 2 known exploit references for CVE-2023-26477, including 2 in-the-wild exploitations 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-2023-26477?

CVE-2023-26477 has an EPSS (Exploit Prediction Scoring System) score of 74.8%, 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-2023-26477?

CVE-2023-26477 is classified as CWE-95 (CWE-95), Code Injection (CWE-94). These weakness types 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-2023-26477 published, and has it been updated?

CVE-2023-26477 was published on March 2, 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-2023-26477 — xwiki-platform-flamingo-t…

CRITICALFix: xwiki/xwiki-platform@ea2e615

CVE-2023-26477 is a critical-severity (CVSS 10) CWE-95 vulnerability in org.xwiki.platform:xwiki-platform-flamingo-theme-ui. 2 public exploit or proof-of-concept references are indexed, so weaponization risk is real. A fix is available for org.xwiki.platform:xwiki-platform-flamingo-theme-ui — see the affected versions and patch details below.

org.xwiki.platform:xwiki-platform-flamingo-theme-ui Eval Injection vulnerability

Also known asGHSA-x2qm-r4wx-8gpg

Published

Mar 2, 2023

Updated

Oct 28, 2026

Affected

3 pkgs

Patched

3 / 3

Exploits

2 known

Exploitation data as of Oct 30, 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-2023-26477.

EPSS Exploitation Probability

via FIRST.org ↗

74.8%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

3 pkgs affected

☕org.xwiki.platform:xwiki-platform-flamingo-theme-ui☕org.xwiki.platform:xwiki-platform-flamingo-theme-ui☕org.xwiki.platform:xwiki-platform-flamingo-theme-ui

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

It's possible to inject arbitrary wiki syntax including Groovy, Python and Velocity script macros via the newThemeName request parameter (URL parameter), in combination with additional parameters form_token=1&action=create.

For instance: http://127.0.0.1:8080/xwiki/bin/view/FlamingoThemesCode/WebHomeSheet?newThemeName=foo%22%2F%7D%7D%7B%7Basync%20async%3D%22true%22%20cached%3D%22false%22%20context%3D%22doc.reference%22%7D%7D%7B%7Bgroovy%7D%7Dprintln(%22hello%20from%20groovy!%22)%7B%7B%2Fgroovy%7D%7D%7B%7B%2Fasync%7D%7D&form_token=1&action=create will execute the following groovy code: println("hello from groovy!") on the server.

Patches

This has been patched in the supported versions 13.10.10, 14.9-rc-1, and 14.4.6.

Workarounds

It is possible to edit FlamingoThemesCode.WebHomeSheet and manually perform the changes from the patch fixing the issue.

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

Affected Packages

3 total 3 fixed

Ecosystem	Package	Vulnerable range	Fix
☕Maven	`org.xwiki.platform:xwiki-platform-flamingo-theme-ui`	≥ 6.2.4&&< 13.10.10	13.10.10`org.xwiki.platform:xwiki-platform-flamingo-theme-ui:13.10.10`
☕Maven	`org.xwiki.platform:xwiki-platform-flamingo-theme-ui`	≥ 14.0&&< 14.4.6	14.4.6`org.xwiki.platform:xwiki-platform-flamingo-theme-ui:14.4.6`
☕Maven	`org.xwiki.platform:xwiki-platform-flamingo-theme-ui`	≥ 14.5&&< 14.9-rc-1	14.9-rc-1`org.xwiki.platform:xwiki-platform-flamingo-theme-ui:14.9-rc-1`

Affected Products

1 product · 3 configurations

Application

xwikixwiki

≥ 14.5 && < 14.9

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 Platform is a generic wiki platform. Starting in versions 6.3-rc-1…

jira.xwiki.orgNVDMar 2023

Report on github.com

github.comNVDMar 2023

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-flamingo-theme-ui, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update org.xwiki.platform:xwiki-platform-flamingo-theme-ui to 13.10.10 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-26477 is resolved across your whole dependency graph.
Workarounds
Stop passing untrusted input into the interpreter or shell: call the affected binary with an argument array rather than a composed command string, reject anything outside a strict allowlist of expected values, and run the component under an account that cannot reach beyond the work it legitimately does.

Frequently Asked Questions

### Impact It's possible to inject arbitrary wiki syntax including Groovy, Python and Velocity script macros via the `newThemeName` request parameter (URL parameter), in combination with additional parameters `form_token=1&action=create`. For instance: [http://127.0.0.1:8080/xwiki/bin/view/FlamingoThemesCode/WebHomeSheet?newThemeName=foo%22%2F%7D%7D%7B%7Basync%20async%3D%22true%22%20cached%3D%22false%22%20context%3D%22doc.reference%22%7D%7D%7B%7Bgroovy%7D%7Dprintln(%22hello%20from%20groovy!%22)%7B%7B%2Fgroovy%7D%7D%7B%7B%2Fasync%7D%7D&form_token=1&action=create](http://127.0.0.1:8080/xwiki/bi