CVE-2026-7307 Keycloak: keycloak: denial of service via specially crafted saml input
Remote unauthenticated attackers can cause denial of service in Keycloak by sending crafted SAML XML input, leading to high CPU usage and thread starvation.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-7307?
CVE-2026-7307 is a high-severity denial of service vulnerability in Redhat Build of Keycloak, published on 19 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
A flaw was found in Keycloak. A remote, unauthenticated attacker can send a specially crafted XML input to the Security Assertion Markup Language (SAML) endpoint. This malicious input can cause high CPU usage and worker thread starvation, leading to a Denial of Service (DoS) where the server becomes unavailable.
Weakness: CWE-1286
Which versions are affected by CVE-2026-7307?
3 open source packages ship an affected version, including org.keycloak:keycloak-saml-core and keycloak. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
org.keycloak:keycloak-saml-core Maven | All versions | 26.6.2 |
org.keycloak:keycloak-saml-core Maven | All versions | 26.6.2 |
keycloak Bitnami | From 26.4.0 | 26.4.12 |
Products include Redhat Build of Keycloak.
How do I fix CVE-2026-7307?
Upgrade org.keycloak:keycloak-saml-core to 26.6.2 or later.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-7307 being exploited?
There is no known exploitation of CVE-2026-7307 in the wild and no public exploit code.
Other vulnerabilities in Redhat Build of Keycloak
- CVE-2026-15572 Keycloak-services: keycloak-services: dcr protocol mapper type-swap policy bypass allows privilege escalation
- CVE-2026-3047 Keycloak SAML Broken has Authentication Bypass by Primary Weakness
- CVE-2026-15573 Keycloak-services: keycloak-services: authorization bypass via unnormalized uri matching in pathmatcher
- CVE-2026-16102 Keycloak-services: keycloak-services: default dcr policy allows role forgery via user property mappers
- CVE-2026-1609 Org.keycloak/keycloak-quarkus-server: keycloak: unauthorized access via jwt authorization grant with disabled users
Sources
Also known as BIT-keycloak-2026-7307, ECHO-d887-ab34-0a8f, GHSA-p5mv-gj8j-xqgf, MINI-43hq-jpvw-fq2f, MINI-5vwq-w5p9-wcxq.