CVE-2026-24329: WildFly-Core DOS Vulnerability

CVE-2026-24329 Overview

CVE-2026-24329 is a denial-of-service vulnerability in wildfly-core, the runtime foundation for the WildFly application server. An authenticated administrative user can inject a malformed payload into the Inet Address field through the Management Model. The payload is persisted to the standalone.xml configuration file, causing the server to crash on the next startup attempt.

Recovery requires manual intervention because the corrupted configuration file prevents the server from restarting cleanly. The flaw is categorized under CWE-91: XML Injection.

Critical Impact
An authenticated administrator can render a WildFly instance unrecoverable by writing a malformed Inet Address value into standalone.xml, causing a persistent denial of service until the configuration is manually repaired.

Affected Products

Red Hat WildFly Core (specific versions not enumerated in the advisory)
Products bundling wildfly-core, including Red Hat JBoss Enterprise Application Platform
Downstream distributions embedding the affected management subsystem

Discovery Timeline

2026-08-11 - CVE-2026-24329 published to the National Vulnerability Database (NVD)
2026-08-12 - Last updated in NVD database

Technical Details for CVE-2026-24329

Vulnerability Analysis

The vulnerability resides in the Management Model handling of the Inet Address attribute. WildFly persists management operations to standalone.xml so configuration state survives restarts. The management layer accepts a malformed payload for the Inet Address field without validating that the value produces well-formed XML.

Once written, the corrupted XML prevents the parser from loading the configuration. WildFly cannot complete boot, and the server enters an unrecoverable state. Administrators must edit standalone.xml by hand or restore a backup to resume operation.

Exploitation requires high privileges because the attacker must authenticate as an administrative user with access to the Management Model. No user interaction is required, and the attack can be delivered over the network via the management interface.

Root Cause

The root cause is missing input validation on the Inet Address field before the value is serialized into standalone.xml. The management subsystem trusts caller-supplied data and writes it directly into the configuration document. The parser then fails to consume the resulting XML on restart, mapping to CWE-91: XML Injection.

Attack Vector

An authenticated administrator submits a management operation that sets the Inet Address attribute to a crafted string containing characters that break XML well-formedness or violate schema expectations. WildFly commits the operation to standalone.xml. On the next reload or restart, the parser rejects the file and the server fails to start.

The technical details of the malformed payload are described in the Red Hat CVE-2026-24329 Advisory and the Red Hat Bug Report #2431938. No public proof-of-concept exploit code is available.

Detection Methods for CVE-2026-24329

Indicators of Compromise

Unexpected modifications to standalone.xml containing malformed characters or unescaped XML metacharacters in Inet Address attributes
WildFly startup failures with XML parser exceptions referencing the configuration file
Management audit log entries showing write operations to Inet Address attributes from administrative accounts
Sudden transition of a WildFly instance from healthy to failed-to-start state without a scheduled change

Detection Strategies

Monitor the WildFly management audit log for write operations targeting Inet Address attributes and correlate with change tickets
Track file integrity on standalone.xml and alert on modifications outside approved change windows
Parse WildFly boot logs for XML SAXParseException or XMLStreamException entries that indicate configuration corruption

Monitoring Recommendations

Forward WildFly management audit logs and server boot logs to a centralized SIEM for correlation with administrative activity
Baseline the expected content and structure of standalone.xml and alert on schema-violating changes
Alert on repeated administrative authentication events from unusual sources targeting the management interface on ports 9990 and 9993

How to Mitigate CVE-2026-24329

Immediate Actions Required

Apply vendor updates from Red Hat as referenced in the Red Hat CVE-2026-24329 Advisory once available for your distribution
Restrict access to the WildFly management interface to trusted administrative networks only
Enforce least privilege on management realm accounts and rotate credentials for any account that does not require write access to network configuration
Take and verify offline backups of standalone.xml so recovery does not depend on manual reconstruction

Patch Information

Red Hat tracks remediation in the Red Hat CVE-2026-24329 Advisory and Red Hat Bug Report #2431938. Administrators should consult these references for fixed package versions of WildFly Core and any Red Hat products that embed it.

Workarounds

Limit membership in the management realm to accounts that strictly require administrative access
Front the management interface with network access controls, such as firewall rules or a bastion host, so only approved operators can reach ports 9990 and 9993
Enable configuration file versioning through the WildFly history directory and validate standalone.xml after every administrative change
Deploy configuration-as-code pipelines that validate management operations against a schema before applying them to production

bash

# Restrict the WildFly management interface to a specific administrative subnet
# Example iptables rule blocking public access to the management ports
iptables -A INPUT -p tcp --dport 9990 -s 10.10.0.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 9993 -s 10.10.0.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 9990 -j DROP
iptables -A INPUT -p tcp --dport 9993 -j DROP

# Verify standalone.xml is well-formed after administrative changes
xmllint --noout /opt/wildfly/standalone/configuration/standalone.xml