Staging Environment: Content and features may be unstable or change without notice.
Advisory details: github_osv / GHSA-m6qj-3mpp-57v8
Advisory ID github_osv/GHSA-m6qj-3mpp-57v8
Aliases CVE-2026-9087
Summary Keycloak: Insufficient verification proof scoping enables identity provider account linking attack and account compromise A flaw was found in Keycloak. The cross-session verification proof is keyed only by (local userId, idpAlias) and is not bound to the upstream identity that was actually verified, so a second upstream account on the same IdP can consume it and get linked to the victim's local account.
Status Published
Exploitability 0.5
Weighted Severity 5.8
Risk 2.9
Affected and Fixed Packages Package Details
Introduced and Fixed Package Commit Patches Package Commit Patches Details
Weaknesses (1)
CWE-639 Authorization Bypass Through User-Controlled Key
System Score Found at
cvssv3.1 6.4 https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/05/GHSA-m6qj-3mpp-57v8/GHSA-m6qj-3mpp-57v8.json
generic_textual MODERATE
Reference id Reference type URL
https://access.redhat.com/errata/RHSA-2026:30049
https://access.redhat.com/errata/RHSA-2026:30050
https://github.com/keycloak/keycloak
https://github.com/keycloak/keycloak/commit/37dabf59d0b5ca3e5b3b272bcd3b2580e67b94dd
https://github.com/keycloak/keycloak/releases/tag/26.6.3
CVE-2026-9087 Advisory https://access.redhat.com/security/cve/CVE-2026-9087
CVE-2026-9087 https://nvd.nist.gov/vuln/detail/CVE-2026-9087
RHSA-2026:25097 Advisory https://access.redhat.com/errata/RHSA-2026:25097
RHSA-2026:25098 Advisory https://access.redhat.com/errata/RHSA-2026:25098
show_bug.cgi?id=2480172 Bug https://bugzilla.redhat.com/show_bug.cgi?id=2480172
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:H/PR:L/UI:R/S:U/C:H/I:H/A:N Found at https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/05/GHSA-m6qj-3mpp-57v8/GHSA-m6qj-3mpp-57v8.json
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:T/P:M/B:A/M:M/D:T/2026-05-21T14:01:27Z/

Decision: Track

Source URL: https://github.com/cisagov/vulnrichment/blob/develop/2026/9xxx/CVE-2026-9087.json

Source Advisory: vulnrichment/CVE-2026-9087

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

Vector: SSVCv2/E:N/A:N/T:T/P:M/B:A/M:M/D:T/2026-05-21T14:01:27Z/

Decision: Track

Source URL: https://github.com/cisagov/vulnrichment/blob/develop/2026/9xxx/CVE-2026-9087.json

Source Advisory: vulnrichment/CVE-2026-9087

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