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Advisory details: vulnrichment / CVE-2026-9798
Advisory ID vulnrichment/CVE-2026-9798
Aliases
Summary A flaw was found in Keycloak, an open-source identity and access management solution. When a user account is temporarily locked due to repeated failed login attempts, an attacker with valid client credentials can exploit the Client-Initiated Backchannel Authentication (CIBA) flow to bypass this brute-force protection. This allows continued authentication attempts and token issuance even when the account should be locked, potentially enabling further unauthorized access attempts.
Status Published
Exploitability 0.5
Weighted Severity 0.0
Risk
Affected and Fixed Packages Package Details
Introduced and Fixed Package Commit Patches Package Commit Patches Details
Weaknesses (1)
CWE-305 Authentication Bypass by Primary Weakness
System Score Found at
cvssv3.1 4.3
ssvc Track
Reference id Reference type URL
https://access.redhat.com/security/cve/CVE-2026-9798
https://bugzilla.redhat.com/show_bug.cgi?id=2482470
cpe:/a:redhat:build_keycloak:26.4::el9 Other https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:/a:redhat:build_keycloak:26.4::el9
cpe:/a:redhat:build_keycloak:26.6::el9 Other https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:/a:redhat:build_keycloak:26.6::el9
RHSA-2026:50846 Advisory https://access.redhat.com/errata/RHSA-2026:50846
RHSA-2026:50847 Advisory https://access.redhat.com/errata/RHSA-2026:50847
RHSA-2026:50848 Advisory https://access.redhat.com/errata/RHSA-2026:50848
RHSA-2026:50849 Advisory https://access.redhat.com/errata/RHSA-2026:50849
No exploits are available.

No EPSS data available for this advisory.

Patch URL
There are no known patches.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N Found at None
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:N/T:P/P:M/B:A/M:M/D:T/2026-05-29T18:29:49Z/ Found at None

Vector: SSVCv2/E:N/A:N/T:P/P:M/B:A/M:M/D:T/2026-05-29T18:29:49Z/

Decision: Track

Source URL: https://github.com/cisagov/vulnrichment/blob/develop/2026/9xxx/CVE-2026-9798.json

Source Advisory: vulnrichment/CVE-2026-9798

View SSVC decision tree 
[{'Exploitation': 'none'},
 {'Automatable': 'no'},
 {'Technical Impact': 'partial'},
 {'Mission Prevalence': 'minimal'},
 {'Public Well-being Impact': 'material'},
 {'Mission & Well-being': 'medium'}]