8.8

CVE-2026-9704

Keycloak: keycloak: privilege escalation due to oversized subject_token jwt

A flaw was found in Keycloak. An authenticated user with low privileges can exploit this vulnerability by sending an oversized subject_token JSON Web Token (JWT) to the TokenEndpoint. When the token exceeds a 4000-character limit, it is silently dropped, causing the system to fall back to client credentials. This allows the user to gain the permissions of the client's service account, leading to privilege escalation.
Daten sind bereitgestellt durch National Vulnerability Database (NVD)
Redhat ≫ Build Of Keycloak Version- SwEdition-
VulnDex Vulnerability Enrichment
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Zu dieser CVE wurde keine Warnung gefunden.
EPSS Metriken
Typ Quelle Score Percentile
EPSS FIRST.org 0.32% 0.237
CVSS Metriken
Quelle Base Score Exploit Score Impact Score Vector String
nvd@nist.gov 8.8 2.8 5.9
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
secalert@redhat.com 6.8 1.6 5.2
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N
CWE-1284 Improper Validation of Specified Quantity in Input

The product receives input that is expected to specify a quantity (such as size or length), but it does not validate or incorrectly validates that the quantity has the required properties.

https://access.redhat.com/security/cve/CVE-2026-9704
Vendor Advisory
Mitigation
https://bugzilla.redhat.com/show_bug.cgi?id=2481877
Vendor Advisory
Issue Tracking
https://access.redhat.com/errata/RHSA-2026:25098
https://access.redhat.com/errata/RHSA-2026:25097
https://access.redhat.com/errata/RHSA-2026:30049
https://access.redhat.com/errata/RHSA-2026:30050