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Advisory details: vulnrichment / CVE-2026-2603
Advisory ID vulnrichment/CVE-2026-2603
Aliases
Summary A flaw was found in Keycloak. A remote attacker could bypass security controls by sending a valid SAML response from an external Identity Provider (IdP) to the Keycloak SAML endpoint for IdP-initiated broker logins. This allows the attacker to complete broker logins even when the SAML Identity Provider is disabled, leading to unauthorized authentication.
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-306 Missing Authentication for Critical Function
System Score Found at
cvssv3.1 8.1
ssvc Track*
Reference id Reference type URL
cpe:/a:redhat:build_keycloak:26.2::el9 Other https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:/a:redhat:build_keycloak:26.2::el9
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
CVE-2026-2603 Advisory https://access.redhat.com/security/cve/CVE-2026-2603
RHSA-2026:3925 https://access.redhat.com/errata/RHSA-2026:3925
RHSA-2026:3926 https://access.redhat.com/errata/RHSA-2026:3926
RHSA-2026:3947 https://access.redhat.com/errata/RHSA-2026:3947
RHSA-2026:3948 https://access.redhat.com/errata/RHSA-2026:3948
show_bug.cgi?id=2440300 Bug https://bugzilla.redhat.com/show_bug.cgi?id=2440300
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:L/UI:N/S:U/C:H/I:H/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:P/A:N/T:T/P:M/B:A/M:M/D:R/2026-03-18T14:10:05Z/ Found at None

Vector: SSVCv2/E:P/A:N/T:T/P:M/B:A/M:M/D:R/2026-03-18T14:10:05Z/

Decision: Track*

Source URL: https://github.com/cisagov/vulnrichment/blob/develop/2026/2xxx/CVE-2026-2603.json

Source Advisory: vulnrichment/CVE-2026-2603

View SSVC decision tree 
[{'Exploitation': 'poc'},
 {'Automatable': 'no'},
 {'Technical Impact': 'total'},
 {'Mission Prevalence': 'minimal'},
 {'Public Well-being Impact': 'material'},
 {'Mission & Well-being': 'medium'}]