Advisory details:
github_osv / GHSA-cpf7-j4cf-vqx4
| Advisory ID | github_osv/GHSA-cpf7-j4cf-vqx4 |
| Aliases |
CVE-2026-9803
|
| Summary | Keycloak has an Out-of-bounds Read A flaw was found in Keycloak's ClientRegistrationAuth component. A remote unauthenticated attacker can exploit this vulnerability by sending a specially crafted POST request with a malformed 'Authorization: Bearer' header to any client registration endpoint. This can lead to an ArrayIndexOutOfBoundsException, causing the server to return an HTTP 500 error and resulting in a Denial of Service (DoS) for the affected service. |
| Status | Published |
| Exploitability | 0.5 |
| Weighted Severity | 4.8 |
| Risk | 2.4 |
| Affected and Fixed Packages | Package Details |
| Introduced and Fixed Package Commit Patches | Package Commit Patches Details |
| CWE-125 | Out-of-bounds Read |
| System | Score | Found at |
|---|---|---|
| cvssv3.1 | 5.3 | https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/05/GHSA-cpf7-j4cf-vqx4/GHSA-cpf7-j4cf-vqx4.json |
| generic_textual | MODERATE |
No EPSS data available for this advisory.
| Patch URL | |
|---|---|
| There are no known patches. | |
| Attack Vector (AV) | Attack Complexity (AC) | Privileges Required (PR) | User Interaction (UI) | Scope (S) | Confidentiality Impact (C) | Integrity Impact (I) | Availability Impact (A) |
|---|---|---|---|---|---|---|---|
network adjacent_network local physical |
low high |
none low high |
none required |
unchanged changed |
high low none |
high low none |
high low none |
Vector: SSVCv2/E:N/A:Y/T:P/P:M/B:A/M:M/D:T/2026-05-28T13:09:44Z/
Decision: Track
Source URL: https://github.com/cisagov/vulnrichment/blob/develop/2026/9xxx/CVE-2026-9803.json
Source Advisory: vulnrichment/CVE-2026-9803
[{'Exploitation': 'none'},
{'Automatable': 'yes'},
{'Technical Impact': 'partial'},
{'Mission Prevalence': 'minimal'},
{'Public Well-being Impact': 'material'},
{'Mission & Well-being': 'medium'}]