Keycloak: keycloak: privilege escalation due to oversized subject_token jwt (Red Hat Red Hat build of Keycloak 26.4)
En bref
- Source
- NVD
- EPSS
- EPSS 0.32 % · centile 25 ()
- État
- PUBLISHED
- Publiée
- Mise à jour
- Attribuée par
- redhat
- Statut NVD
- Modified
Description
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.
Faiblesses (CWE)
- CWE-1284 — Validation incorrecte d'une quantité spécifiée en entrée
Références
Scores
| Version | Score | Vecteur | Évalué par |
|---|---|---|---|
| CVSS 3.1 | MEDIUM 6.8 | CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N | redhat |
| CVSS 3.1 | MEDIUM 6.8 | CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N | NVD · secalert@redhat.com (Secondary) |
| CVSS 3.1 | HIGH 8.8 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H | NVD · nvd@nist.gov (Primary) |
Avis
- GHSA-rr5q-3xwr-f323 — Keycloak Vulnerable to Improper Validation of Specified Quantity in Input
Références européennes
- ENISA EUVD · EUVD-2026-32300
- GCVE · GCVE-0-2026-9704
Configurations affectées (CPE NVD)
cpe:2.3:a:redhat:build_of_keycloak:-:*:*:*:-:*:*:*
Produits affectés
| Produit | Versions |
|---|---|
| Red Hat · Red Hat build of Keycloak 26.4 | unaffected 26.4.13-1 < * |
| Red Hat · Red Hat build of Keycloak 26.4 | unaffected 26.4-19 < * |
| Red Hat · Red Hat build of Keycloak 26.4 | unaffected 26.4-19 < * |
| Red Hat · Red Hat build of Keycloak 26.4.13 | |
| Red Hat · Red Hat build of Keycloak 26.6 | unaffected 26.6.3-3 < * |
| Red Hat · Red Hat build of Keycloak 26.6 | unaffected 26.6-6 < * |
| Red Hat · Red Hat build of Keycloak 26.6 | unaffected 26.6-6 < * |
| Red Hat · Red Hat build of Keycloak 26.6.3 |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |