CVE-2026-7571 (GCVE-0-2026-7571)

Vulnerability from cvelistv5 – Published: 2026-05-19 11:01 – Updated: 2026-05-20 16:08
VLAI?
Title
Keycloak: keycloak: access token disclosure and implicit flow bypass via forged client data
Summary
A flaw was found in Keycloak. A low-privilege user, with knowledge of user credentials and client ID, can bypass a security control intended to disable the implicit flow in OpenID Connect (OIDC) clients. By manipulating client data during a session restart, an attacker can obtain an access token that should not be available. This vulnerability can also lead to the exposure of these access tokens in server logs, proxy logs, and HTTP Referrer headers, resulting in sensitive information disclosure.
Severity ?
7.1 (High)
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N
CWE
  • CWE-472 - External Control of Assumed-Immutable Web Parameter
Assigner
References
URL Tags
https://access.redhat.com/errata/RHSA-2026:19596 vendor-advisoryx_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2026:19597 vendor-advisoryx_refsource_REDHAT
https://access.redhat.com/security/cve/CVE-2026-7571 vdb-entryx_refsource_REDHAT
https://bugzilla.redhat.com/show_bug.cgi?id=2464263 issue-trackingx_refsource_REDHAT
Impacted products
Vendor Product Version
Red Hat Red Hat build of Keycloak 26.4 Unaffected: 26.4.12-1 , < * (rpm)
    cpe:/a:redhat:build_keycloak:26.4::el9
 Create a notification for this product.
Red Hat Red Hat build of Keycloak 26.4 Unaffected: 26.4-17 , < * (rpm)
    cpe:/a:redhat:build_keycloak:26.4::el9
 Create a notification for this product.
Red Hat Red Hat build of Keycloak 26.4 Unaffected: 26.4-17 , < * (rpm)
    cpe:/a:redhat:build_keycloak:26.4::el9
 Create a notification for this product.
Red Hat Red Hat build of Keycloak 26.4.12     cpe:/a:redhat:build_keycloak:26.4::el9
 Create a notification for this product.
Date Public ?
2026-05-19 10:50
Credits
Red Hat would like to thank Evan Hendra for reporting this issue.
Show details on NVD website
To clipboard 

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Taxonomy of the tags.




Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



Detection rules are retrieved from Rulezet.