Authorization-code theft via unescaped JARM form action
Published Dec 18, 2023 · Updated Nov 11, 2025
Open redirect in Keycloak before 23.0.4 allows remote authenticated users to steal authorization codes or tokens through crafted JARM requests. The form_post.jwt response mode writes a multiply decoded redirect_uri into an HTML form action without the entity escaping applied to form_post, so an encoded at-sign becomes a hostname delimiter in the browser. A client must permit a wildcard redirect URI, and a victim must open the crafted authorization URL and authenticate; the bounded result is code or token disclosure.
Summary
What happened
Open redirect in Keycloak before 23.0.4 allows remote authenticated users to steal authorization codes or tokens through crafted JARM requests. The form_post.jwt response mode writes a multiply decoded redirect_uri into an HTML form action without the entity escaping applied to form_post, so an encoded at-sign becomes a hostname delimiter in the browser. A client must permit a wildcard redirect URI, and a victim must open the crafted authorization URL and authenticate; the bounded result is code or token disclosure.
The record
- CVE
- CVE-2023-6927
- Published
- Dec 18, 2023
- Updated
- Nov 11, 2025
- Vendor
- Red Hat
- Product
- RHEL-8 based Middleware Containers
- Classifications
- CWE-601, T1528
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Dec 18, 2023CVE publishedPublication date reported by the CVE source.
- Nov 11, 2025Record 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?
What is affected?
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.
Weakness, pattern, technique
Public exploit references
- Omegapoint Keycloak open-redirect proof of conceptfunctional · demonstrated
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Technologies
Your stack
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Your stack
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