CVE-2026-18967

Session hijacking via unchecked OneTimeUse replay

Published Aug 6, 2026 · Updated Aug 6, 2026

Authentication bypass in Red Hat build of Keycloak and JBoss EAP XP allows attackers to hijack sessions via replayed SAML assertions. The IdP-Initiated SAML broker flow neither records consumed OneTimeUse assertion IDs nor rejects an ID presented again. Exploitation requires capture of a valid, unused assertion and replay within its validity window, granting the victim's session privileges.

CVSS severity6.4
Medium
EPSS probability0.14%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authentication bypass in Red Hat build of Keycloak and JBoss EAP XP allows attackers to hijack sessions via replayed SAML assertions. The IdP-Initiated SAML broker flow neither records consumed OneTimeUse assertion IDs nor rejects an ID presented again. Exploitation requires capture of a valid, unused assertion and replay within its validity window, granting the victim's session privileges.

The record

CVE
CVE-2026-18967
Published
Aug 6, 2026
Updated
Aug 6, 2026
Vendor
389 Directory Server
Product
Red Hat JBoss Enterprise Application Platform Expansion Pack
Classifications
CWE-294, T1550.001
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 6, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 6, 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 build of KeycloakAffected versions are unavailable in this record.

Published CVSS scores

8.1NIST NVDCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
6.4Red HatCVSS:3.1/AV:A/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N

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.

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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-294Authentication Bypass by Capture-replay
T1550.001Application Access Token

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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