Unauthenticated Remote Code Execution in Oracle WebLogic Server
CISA: Oracle Corporation WebLogic Server Remote Code Execution Vulnerability
CVSS 3.1
7.5high
EPSS
100%p100
Published
()
KEV added
AI analysis
Oracle WebLogic Server (CVE-2017-10271) contains a remote code execution flaw in its WLS Security component, where an XMLDecoder deserialization bug allows unauthenticated attackers to execute arbitrary code. The flaw is triggered by sending specially crafted XML requests to exposed WebLogic HTTP endpoints, so any instance whose WebLogic ports are reachable by untrusted users is at risk. Successful exploitation yields arbitrary code execution on the application server host, and the bug has been widely leveraged to install cryptominers and ransomware payloads. Organizations running Oracle WebLogic Server — particularly instances directly exposed to the internet — are affected, and the flaw has been on CISA's Known Exploited Vulnerabilities catalog since 2022-02-10 with confirmed ransomware use. Exploitation is assessed as essentially certain in the near term (EPSS 100.0%, 100th percentile), and defenders should treat it as an actively exploited, high-priority issue.
What to do: Apply Oracle's updates for CVE-2017-10271 per Oracle's instructions (the vendor's required action for this KEV entry). Until patched, restrict network access to WebLogic HTTP/admin ports from untrusted networks and limit or remove access to the XML/WSAT endpoints used for exploitation. Because ransomware operators are known to exploit this flaw, review internet-exposed WebLogic instances for signs of compromise, such as unexpected processes, new scheduled tasks, webshells, or ransomware artifacts.
Affected
Oracle WebLogic Server
—
Estimated exposure
large≈tens of thousands of internet-exposed WebLogic Server instances (total deployed install base likely higher, including internal-only servers) — Public internet-wide scans have repeatedly shown tens of thousands of Oracle WebLogic servers reachable on default WebLogic HTTP/admin ports, and WebLogic remains a common enterprise application server, implying a larger number of internal…
Order-of-magnitude estimate by the model from install counts, market share and public scan data it knows; verify before quoting.
Description
Vulnerability in the Oracle WebLogic Server component of Oracle Fusion Middleware (subcomponent: WLS Security). Supported versions that are affected are 10.3.6.0.0, 12.1.3.0.0, 12.2.1.1.0 and 12.2.1.2.0. Easily exploitable vulnerability allows unauthenticated attacker with network access via T3 to compromise Oracle WebLogic Server. Successful attacks of this vulnerability can result in takeover of Oracle WebLogic Server. CVSS 3.0 Base Score 7.5 (Availability impacts). CVSS Vector: (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).
CISA added actively exploited Oracle WebLogic flaw CVE-2026-21962 (CVSS 10.0) to its KEV catalog, letting unauthenticated attackers access or modify critical data.
CISA added CVE-2026-21962, a CVSS 10.0 improper access control flaw in Oracle HTTP Server and Oracle WebLogic Server Proxy Plug-in, to its Known Exploited Vulnerabilities catalog, citing evidence of active exploitation. Oracle shipped patches in January 2026, and GreyNoise, CloudSEK, and SOCRadar have since reported exploitation attempts, including a lone IP scanning multiple WebLogic, Ivanti, GNU InetUtils, and GLPI vulnerabilities. The flaw is also among several exploited by a China-linked actor delivering the SNOWLIGHT downloader to government and commercial infrastructure in more than 100 countries. Federal civilian agencies must apply fixes by August 27, 2026 under BOD 26-04.
CISA added actively exploited CVE-2026-21962, a CVSS 10.0 unauthenticated flaw in Oracle HTTP Server and WebLogic Proxy Plug-in, to KEV with an August 27 deadline.
CISA added CVE-2026-21962 (CVSS 10.0), an improper access control vulnerability in Oracle HTTP Server and the Oracle WebLogic Server Proxy Plug-in, to its Known Exploited Vulnerabilities catalog and ordered federal agencies to remediate by August 27, 2026. The unauthenticated flaw allows remote attackers with network access to create, delete, or modify critical data, potentially gain broad access, and cause a scope change to other systems; affected versions are 12.2.1.4.0, 14.1.1.0.0 and 14.1.2.0.0. CloudSEK honeypot data from January-February 2026 showed widespread exploitation of the flaw alongside older WebLogic RCEs including CVE-2020-14882/14883, CVE-2020-2551, and CVE-2017-10271.