CVE-2021-23926 — xmlbeans
CRITICALCVE-2021-23926 is a critical-severity (CVSS 9.1) CWE-776 vulnerability in org.apache.xmlbeans:xmlbeans. A fix is available for org.apache.xmlbeans:xmlbeans — see the affected versions and patch details below.
Improper Restriction of Recursive Entity References in Apache XMLBeans
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2021-23926 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
org.apache.xmlbeans:xmlbeansReal-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
The XML parsers used by XMLBeans up to version 2.6.0 did not set the properties needed to protect the user from malicious XML input. Vulnerabilities include possibilities for XML Entity Expansion attacks. Affects XMLBeans up to and including v2.6.0.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | org.apache.xmlbeans:xmlbeans | all versions | 3.0.0org.apache.xmlbeans:xmlbeans:3.0.0 |
Affected Products
xmlbeansapachedebian linuxdebianoncommand unified manager core packagenetappsnap creator frameworknetappsnapmanagernetappmiddleware common libraries and toolsoracleDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.apache.xmlbeans:xmlbeans, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update org.apache.xmlbeans:xmlbeans to 3.0.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-23926 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.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
Affected users are advised to update to Apache XMLBeans 3.0.0 or above, which fixes this vulnerability.Source: Red Hat security advisory for CVE-2021-23926 (CC BY 4.0)
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat Fuse 7.10 | xmlbeans | RHSA-2021:5134 |
Frequently Asked Questions
Is CVE-2021-23926 in your dependencies?
Find it across Maven, including transitive dependencies.