CVE-2026-15555

Adjacent-network RCE via unfiltered River session deserialization

Published Aug 11, 2026 · Updated Aug 11, 2026

Deserialization in Red Hat JBoss Enterprise Application Platform allows remote attackers to execute code through cluster traffic. The Infinispan session-replication path passes replicated data to the JBoss Marshalling River unmarshaller without a class filter. Default JGroups stacks omit authentication, allowing a network-adjacent attacker to join the cluster and run gadget chains on every node.

CVSS severity8.8
High
EPSS probability0.26%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Deserialization in Red Hat JBoss Enterprise Application Platform allows remote attackers to execute code through cluster traffic. The Infinispan session-replication path passes replicated data to the JBoss Marshalling River unmarshaller without a class filter. Default JGroups stacks omit authentication, allowing a network-adjacent attacker to join the cluster and run gadget chains on every node.

The record

CVE
CVE-2026-15555
Published
Aug 11, 2026
Updated
Aug 11, 2026
Vendor
389 Directory Server
Product
Red Hat JBoss Enterprise Application Platform Expansion Pack
Classifications
CWE-502, CWE-306, T1210
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 11, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 11, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected versions are unavailable in this record. Check the vendor advisory for version and patch details.

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

389 Directory Server · Red Hat JBoss Enterprise Application Platform Expansion PackAffected versions are unavailable in this record.
389 Directory Server · Red Hat JBoss Enterprise Application Platform 8Affected versions are unavailable in this record.
389 Directory Server · Red Hat JBoss Enterprise Application PlatformAffected versions are unavailable in this record.

Published CVSS scores

8.8Red HatCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-502Deserialization of Untrusted Data
CWE-306Missing Authentication for Critical Function
T1210Exploitation of Remote Services

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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