⚠ Reference material — not professional advice. Test in staging, back up first, verify against your specific version. Use your own judgment for your environment.
● High · CVSS 8.1

How to Fix CVE-2026-7504: Open Redirect in Red Hat build of Keycloak 26.2

Other vulnerabilities in the same area that are worth patching alongside this one:

*By Sai Kiran Pandrala*

⚡ At a glance
SeverityCVSS 8.1 - High
Actively exploited?Not currently listed in CISA KEV
AffectedRed Hat build of Keycloak 26.2 - see advisory for affected version ranges
Fixed in26.2.16-1, 26.2-21, 26.2-21, 26.4.12-1, 26.4-17, 26.4-17
Type (CWE)CWE-601: URL Redirection to Untrusted Site ('Open Redirect')

What is CVE-2026-7504?

CVE-2026-7504 is an open-redirect flaw in Red Hat build of Keycloak 26.2. The product forwards users to a URL taken from a parameter without validating the destination, which phishing campaigns use to abuse the product's trusted domain. Vendor description: A flaw was found in Keycloak's URL validation logic during redirect operations. By crafting a malicious request, an attacker could bypass validation to redirect users to unauthorized URLs, potentially leading to the exposure of sensitive information within the domain or facilitating further attacks.

Why this CVE matters

Open redirects on a trusted domain are routinely used by phishing kits to land victims on credential-harvesting pages while bouncing through a domain the victim trusts.

For deployments of Red Hat build of Keycloak 26.2 that have been exposed to the public internet during the disclosure window, the operating assumption should be that scanning has already happened. Even where exploitation has not been publicly observed, scanning for the vulnerable fingerprint is cheap and routine. Patching closes the door; log review and credential rotation close out the rest of the response.

Am I affected?

Check your installed Red Hat build of Keycloak 26.2 version against the affected ranges in the vendor advisory linked below. If you cannot determine the version, treat the system as potentially affected and apply the patched build.

Open Red Hat build of Keycloak 26.2's About dialog or run the vendor-documented version-check command. Compare the result against the affected ranges in the advisory.

How to fix CVE-2026-7504

  1. Read the vendor advisory in full: https://access.redhat.com/errata/RHSA-2026:19594
  2. Upgrade Red Hat build of Keycloak 26.2 to 26.2.16-1, 26.2-21, 26.2-21, 26.4.12-1, 26.4-17, 26.4-17 or a later version listed in the vendor advisory.
  3. Back up the configuration (and database, where applicable) before upgrading.
  4. Apply the patch in a maintenance window. For HA pairs, upgrade the standby node first, fail over, then upgrade the former primary.
  5. Restart the affected service so the patched binary loads, then verify the new version (see verification section).

Linux package upgrade

The vendor advisory (https://access.redhat.com/errata/RHSA-2026:19594) names the patched build as Red Hat build of Keycloak 26.2 26.2.16-1, Red Hat build of Keycloak 26.2 26.2-21, Red Hat build of Keycloak 26.4 26.4.12-1, and 1 more (see References).


# Ubuntu / Debian
sudo apt-get update
sudo apt-get install --only-upgrade redhatbuildofkeycloak262
dpkg -s redhatbuildofkeycloak262 | grep -i version

# RHEL / Rocky / AlmaLinux / Fedora
sudo dnf upgrade --refresh redhatbuildofkeycloak262 -y
rpm -q redhatbuildofkeycloak262

# openSUSE
sudo zypper refresh && sudo zypper update redhatbuildofkeycloak262

# Restart the service that loads the patched binary
sudo systemctl restart redhatbuildofkeycloak262 2>/dev/null || true
sudo systemctl status redhatbuildofkeycloak262 --no-pager 2>/dev/null || true


# Vendor advisory: https://access.redhat.com/errata/RHSA-2026:19594
# Container deployments: rebuild with the patched package layer, then roll the workload.
docker pull <your-registry>/redhatbuildofkeycloak262:<patched-tag>
docker stop <app> && docker rm <app>
docker run -d --name <app> <your-registry>/redhatbuildofkeycloak262:<patched-tag>

# Kubernetes
kubectl set image deployment/<deployment-name> redhatbuildofkeycloak262=<your-registry>/redhatbuildofkeycloak262:<patched-tag>
kubectl rollout status deployment/<deployment-name>

Verify the fix landed


# Vendor advisory: https://access.redhat.com/errata/RHSA-2026:19594
# 1. Compare the running version against the fixed build named above.
#    (Replace the version probe with the platform-specific command from the block above.)

# 2. Re-scan with your vulnerability scanner (Nessus, Qualys, Tenable, OpenVAS).
#    The scanner should no longer flag this CVE on the patched target.

# 3. Inspect recent service / kernel logs for crash loops or rollback events.
journalctl -u <service> --since "10 minutes ago"
dmesg --since "10 minutes ago"

If you cannot patch immediately

Block the redirect parameter at a reverse proxy, or strip it from inbound requests. Patch as the durable fix.

How to verify the fix worked

If your installation was internet-reachable during the disclosure window, treat log review as part of the remediation rather than an optional follow-up. Look for log entries that do not match your normal request patterns, especially repeated requests to the same uncommon endpoint, and any administrative changes you cannot tie back to a known operator.

Frequently asked questions

Is CVE-2026-7504 being exploited in the wild?

Public exploitation has not been confirmed by CISA at the time of writing. Treat the patch as time-sensitive anyway; reports often lag actual abuse.

Will a WAF or IDS rule fully mitigate CVE-2026-7504?

No. Network-layer filters can reduce noise and slow opportunistic scanners, but they will not stop a determined attacker. The vendor patch is the only durable fix.

How long should I plan for the upgrade?

Typical vendor-documented upgrade windows for Red Hat build of Keycloak 26.2 run from a few minutes to under an hour depending on cluster size. Test in a staging environment first and follow the vendor's documented HA upgrade order.

References

*This guide was assembled from the official vendor advisory, the NVD record, and the CISA KEV catalog entry on 2026-05-25. Always confirm against the vendor advisory before applying changes in production.*