CVE-2026-16102: Improper Access Control
Source GCVE Database
Not known to be exploited · CVSS 8.1 High · fixed in Red Hat build of Keycloak 26.4 package updates : patch Red Hat build of Keycloak 26.4 soon.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 0.4% chance of exploitation in 30 days – higher than 39% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 26.4.14
CVSS:3.1/AV:N/AC:L/PR:L/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
Weaponised: 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 26 Oct 2026.
What to do
Patches and advisories
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– |
Description
A flaw was found in the Dynamic Client Registration (DCR) component of Keycloak, an identity and access management solution. The default DCR policy fails to properly validate the claim path for User Property mappers, allowing them to write values to sensitive internal claim locations. An attacker with a standard user account and a limited Initial Access Token can exploit this to forge administrative roles in their access token. This allows the attacker to take over other clients, steal confidential secrets, and potentially gain full administrative control over the realm.
References
- nvd.nist.gov/vuln/detail/CVE-2026-16102 (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)
- access.redhat.com/security/cve/CVE-2026-16102 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2501735 (opens in a new tab)