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CVE-2026-16102

HIGH 8.1

Published 2026-08-05 · Last modified 2026-08-21

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.

ELEVATED IMPACT

Severe if exploited (CVSS 8.1), but no known exploitation and low modeled probability. Patch on a normal cadence.

Exploitation likelihood

0.3%chance of exploitation in 30 days · 17th percentile

○ In CISA KEV ○ Public exploit / PoC

Impact if exploited

8.1CVSS 3.1 · HIGH

  • ConfidentialityHigh
  • IntegrityHigh
  • AvailabilityNone

What an attacker needs

  • ✓Access: Reachable over the network — no local access needed
  • ⚠Privileges: Requires a low-privilege account
  • ✓User interaction: No user interaction needed
  • ✓Complexity: No special conditions — reliably repeatable

✓ lowers the bar for an attacker · ⚠ raises it

Proof of concept & exploit code

Test against your own equipment

curl -s https://vulnpedia.com/cve/CVE-2026-16102/poc.jsonMachine-readable PoC index for this CVE (for automation).

Listed for defensive triage, patch verification, and authorized testing on systems you own. Machine-readable: /cve/CVE-2026-16102/poc.json

Affected

Vendors Red Hat Redhat

Products Red Hat Build Of Keycloak 26.4 Red Hat Build Of Keycloak 26.4.14 Red Hat Build Of Keycloak 26.6 Red Hat Build Of Keycloak 26.6.5 Red Hat Data Grid 8 Red Hat Jboss Enterprise Application Platform Expansion Pack Red Hat Single Sign On 7 Build Of Keycloak Data Grid Jboss Enterprise Application Platform Expansion Pack Single Sign On

Weakness (CWE)

  • CWE-284: Improper Access Control

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

Known Affected Software Configurations

VendorProductVersion range
RedhatBuild Of Keycloak≥ 26.4 and < 26.4.14
RedhatBuild Of Keycloak≥ 26.6 and < 26.6.5
RedhatData Grid8.0
RedhatJboss Enterprise Application Platform Expansion Pack*
RedhatSingle Sign On7.0

All CVSS metrics

  • HIGH 8.1 v3.1 · CNA Primary
    CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
  • HIGH 8.1 v3.1 · NVD Secondary
    CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

References

Advisories

Technical & other

Sources: NVD · CVE.org · EPSS