CVE-2026-16442: Red Hat build of Keycloak 26.4 · Origin Validation Error
Affects Red Hat build of Keycloak 26.4Source CVE Database V5
Not known to be exploited · CVSS 7.4 High.
Data as of 3 Nov 2026, 22:58 UTC
- EPSS
- 0.3% chance of exploitation in 30 days – higher than 24% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:NExploitation evidence
Disclosed: evidence found.
CVE published 5 Aug 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 3 Nov 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Red HatRed Hat build of Keycloak 26.4 | Affected– | Fixed in– |
| Red HatRed Hat build of Keycloak 26.4 | Affected– | Fixed in– |
| Red HatRed Hat build of Keycloak 26.4.14 | Affected– | Fixed in– |
| Red HatRed Hat build of Keycloak 26.6 | Affected– | Fixed in– |
| Red HatRed Hat build of Keycloak 26.6 | Affected– | Fixed in– |
| Red HatRed Hat build of Keycloak 26.6.5 | Affected– | Fixed in– |
AI-suggested
Red Hat currently does not provide a patch or mitigation that meets their criteria for ease of use, applicability, and stability. Users should monitor the Red Hat advisory for updates on fixes. Until a fix is available, no official mitigation is recommended by Red Hat.
Description
A flaw was found in the SAML broker component of Keycloak, which is used to manage identity federation and user authentication. The issue occurs because the IdP-initiated Single Sign-On endpoint fails to check if a provider is restricted to account linking only. This allows an attacker with control over a linked upstream identity to bypass login restrictions and gain full access to a local user account.
References
- access.redhat.com/security/cve/CVE-2026-16442 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2503138 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:50846 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:50847 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:50848 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:50849 (opens in a new tab)