Red Hat build of Keycloak 26.6.8 · Vulnerability
Historical advisory recorded 6 Nov 2026 12:03:43 UTC. Read the latest advisory.
cve-program · CVE-2026-97174
PublishedA flaw was found in the Client-Initiated Backchannel Authentication (CIBA) implementation of Keycloak. The CIBA endpoint fails to properly validate the sub parameter, allowing it to be stored as an additional request parameter. During the token issuance process, this injected value overwrites the legitimate subject identifier. This allows an attacker to authenticate as themselves but receive security tokens belonging to a different victim user, leading to unauthorized account access.
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cve-program · CVE-2026-97174
PublishedKeycloak-services: keycloak-services: ciba sub parameter injection causes attacker authentication to issue victim tokens
A flaw was found in the Client-Initiated Backchannel Authentication (CIBA) implementation of Keycloak. The CIBA endpoint fails to properly validate the sub parameter, allowing it to be stored as an additional request parameter. During the token issuance process, this injected value overwrites the legitimate subject identifier. This allows an attacker to authenticate as themselves but receive security tokens belonging to a different victim user, leading to unauthorized account access.
- Source published
- 5 Nov 2026 17:15:54 UTC
- Source modified
- 6 Nov 2026 10:23:55 UTC
- Saved here
- 6 Nov 2026 12:03:43 UTC
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- CVE Program Terms of Use
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CVSS 3.1 · 6.8 CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N