Keycloak token validation falls back to usernames in stateless tokens
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- High
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- Low · Low · None
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-287.
Summary
Red Hat build of Keycloak 26.6 is affected. Keycloak's TokenManager falls back to the username when the original user ID no longer exists during stateless access token validation, without checking that the identity matches the token subject (CWE-287). An attacker holding an old token can gain access to a newly created service account that reuses the client ID of a previously deleted one, under high attack complexity and with low privileges.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
Description from the CNA
A flaw was found in the TokenManager component of Keycloak, an open-source identity and access management solution. The issue occurs during the validation of stateless access tokens when the original user ID no longer exists. Keycloak incorrectly falls back to using the username to identify the user without verifying if the identity matches the original token subject. This could allow an attacker with an old token to gain access to a newly created service account if it shares the same client ID as a previously deleted one.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Red Hat | Red Hat build of Keycloak 26.6 | — | 26.6.8-2 | Patch available | CNA |
| Red Hat | Red Hat build of Keycloak 26.6 | — | 26.6-24 | Patch available | CNA |
| Red Hat | Red Hat build of Keycloak 26.6 | — | 26.6-24 | Patch available | CNA |
| Red Hat | Red Hat build of Keycloak 26.6.8 | — | — | Not affected | CNA |
| Red Hat | Red Hat build of Keycloak 26.6.8 | — | — | Not affected | CNA |
| Red Hat | Red Hat Single Sign-On 7 | — | — | Not affected | CNA |
- Red Hat build of Keycloak 26.6 VendorRed Hat Affected — Fixed in 26.6.8-2 Patch available CNA
- Red Hat build of Keycloak 26.6 VendorRed Hat Affected — Fixed in 26.6-24 Patch available CNA
- Red Hat build of Keycloak 26.6 VendorRed Hat Affected — Fixed in 26.6-24 Patch available CNA
- Red Hat build of Keycloak 26.6.8 VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat build of Keycloak 26.6.8 VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat Single Sign-On 7 VendorRed Hat Affected — Fixed in — Not affected CNA
Remediation
Red Hat build of Keycloak 26.6 is fixed in 26.6.8-2 and 26.6-24, as described in RHSA-2026:95761 and RHSA-2026:95762.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
Red Hat 2 advisories
- RHSA-2026:95762 Released 2026-11-06 · Red Hat rating ImportantRed Hat build of Keycloak 26.6.8 Images Security Update
- Red Hat build of Keycloak 26.6 rhbk/keycloak-operator-bundle, rhbk/keycloak-rhel9, rhbk/keycloak-rhel9-operator
- RHSA-2026:95761 Released 2026-11-06 · Red Hat rating ImportantRed Hat build of Keycloak 26.6.8 Security Update
- Red Hat build of Keycloak 26.6.8
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat build of Keycloak 26.6 | Fixed | RHSA-2026:95762 |
| Red Hat build of Keycloak 26.6.8 | Fixed | RHSA-2026:95761 |
Not affected: 1 product
- Red Hat Single Sign-On 7
Timeline
- 2026-11-06 Threatist record created from CVE-2026-96447
- 2026-11-06 Alias added: GHSA-7frc-6h33-jg59
- 2026-11-06 Affected versions changed · Red Hat
- 2026-11-06 CVSS score added · Red Hat
- 2026-11-06 Affected versions changed · CNA
- 2026-11-06 1 new reference · CNA
- 2026-11-06 Fix available: RHSA-2026:95761 · Red Hat
- 2026-11-06 Fix available: Red Hat build of Keycloak 26.6.8 · Red Hat
- 2026-11-06 Fix available: rhbk/[email protected], rhbk/[email protected], rhbk/[email protected] · CNA
- 2026-11-06 1 new reference · CNA
- 2026-11-06 CISA SSVC decision points changed
- 2026-11-06 Fix available: RHSA-2026:95762 · Red Hat
- 2026-11-06 Fix available: Red Hat build of Keycloak 26.6 · Red Hat
References
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Sources
- CVE-2026-96447 · CVE Program
- CVE-2026-96447 · NVD
- FIRST EPSS
- GHSA-7frc-6h33-jg59 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-96447 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences