CVE-2026-18203
Low
No strong exploitation signal.
CVSS base
6.5
MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
EPSS — probability of exploitation (30 days)
0.2%
8.0th percentile
CISA KEV
Not listed
Weakness / dates
CWE-863
Published 2026-07-31 · modified 2026-08-07
CVSS breakdown
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
| Attack Vector | N | Network |
| Attack Complexity | L | Low |
| Privileges Required | L | Low |
| User Interaction | N | None |
| Scope | U | Unchanged |
| Confidentiality | N | None |
| Integrity | H | High |
| Availability | N | None |
Timeline
- 2026-07-31 — Published (NVD)
- 2026-08-07 — Last modified (NVD)
Description
A flaw was found in the group policy evaluation logic of Keycloak, an identity and access management solution. When a group policy is set to extend permissions to child groups, the system incorrectly uses a simple text-based prefix check to verify group membership. This allows a user who belongs to a different group with a similar starting name to bypass security checks and gain unauthorized access to administrative functions or protected resources.