CVE-2026-9802
Description
A flaw was found in Keycloak. When revokeRefreshToken=true is enabled and persistent session storage is in use, a server restart can reset internal timing mechanisms. This allows a remote attacker, who has previously captured a user's refresh token, to replay that token even after it has been revoked. Successful exploitation grants the attacker unauthorized access to the victim's account, potentially leading to information disclosure or privilege escalation.
Statement
A flaw in Keycloak, when configured with revokeRefreshToken=true and persistent session storage, allows a remote attacker to regain unauthorized access. Following a full cluster restart, a previously revoked refresh token, if captured by an attacker, can be replayed to bypass security checks. This could lead to unauthorized account access, potentially resulting in information disclosure or privilege escalation.
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 6.8 | N/A | 6.8 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | High | N/A | High |
| Privileges Required | None | N/A | None |
| User Interaction | Required | N/A | Required |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | High | N/A | High |
| Integrity Impact | High | N/A | High |
| Availability Impact | None | N/A | None |
Vector
Red Hat: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N
cve.org: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N
Understanding the Weakness (CWE)
Access Control
Technical Impact: Bypass Protection Mechanism
Acknowledgements
Red Hat would like to thank Gyeongpyo Son for reporting this issue.
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