{"id":"CVE-2026-13759","title":"IBM WebSphere Extreme Scale 8.6.1.0 through 8.6.1.6 ships three ObjectInputStream subclasses (WsObjectInputStream, ObjectStreamPool$ReusableInputStream, ObjectInputStreamResolver) that install no JEP-290 class filter; when Coherence is o…","summary":"IBM WebSphere Extreme Scale 8.6.1.0 through 8.6.1.6 ships three ObjectInputStream subclasses (WsObjectInputStream, ObjectStreamPool$ReusableInputStream, ObjectInputStreamResolver) that install no JEP-290 class filter; when Coherence is o…","severity":"high","cvss":7.5,"cvssVector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H","cwe":["CWE-502"],"vendor":"ibm","product":"websphere_extreme_scale","affected":["websphere_extreme_scale >= 8.6.1.0, <= 8.6.1.6"],"published":"2026-06-30","updated":"2026-07-03","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-13759","references":[{"url":"https://www.ibm.com/support/pages/node/7278595","label":"psirt@us.ibm.com"}],"tags":["nvd"],"epss":0.00546,"epssPercentile":0.44674,"ingestedAt":"2026-07-03T20:53:53.298Z","slug":"CVE-2026-13759","body":"## Overview\n\nIBM WebSphere Extreme Scale 8.6.1.0 through 8.6.1.6 ships three ObjectInputStream subclasses (WsObjectInputStream, ObjectStreamPool$ReusableInputStream, ObjectInputStreamResolver) that install no JEP-290 class filter; when Coherence is on the classpath, multiple RCE gadget chains including RemoteConstructor.readResolve and PriorityQueue/ExtractorComparator are confirmed working, allowing a post-login attacker who can write a session attribute or a LAN-adjacent attacker on the grid replication wire to execute arbitrary code on peer WAS JVMs\n\n## Affected\n\n- `websphere_extreme_scale >= 8.6.1.0, <= 8.6.1.6`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":41,"depthScoreParts":{"impact":41.3,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}