CVE-2026-9704GHSA-RR5Q-3XWR-F323
Keycloak: keycloak: privilege escalation due to oversized subject_token jwt
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Fix
- Fixed in 26.6.3
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
CISA's decision points: whether it is exploited, whether attacks can be automated, and how much control an attacker gets. Assessed (SSVC 2.0.3).What do these mean? →
- Exploitation: none
- Automatable: no
- Technical impact: total
Summary
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.
Timeline
- CVE published
- CISA SSVC assessment
Exploitation: none · Automatable: no · Technical impact: total
- Record last updated
Affected versions
- rhbk/keycloak-operator-bundle
Version range not reported
- rhbk/keycloak-rhel9
Version range not reported
- rhbk/keycloak-rhel9-operator
Version range not reported
- rhbk/keycloak-rhel9
Version range not reported
- rhbk/keycloak-operator-bundle
Version range not reported
- rhbk/keycloak-rhel9
Version range not reported
- rhbk/keycloak-rhel9-operator
Version range not reported
- rhbk/keycloak-rhel9
Version range not reported
- org.keycloak:keycloak-server-spi-privateMaven
fixed in 26.6.3
- org.keycloak:keycloak-servicesMaven
fixed in 26.6.3