Vulnerability · Published May 19, 2026 · Assigned by redhat
CVE-2026-7307Keycloak: keycloak: denial of service via specially crafted saml input
High 7.5
In plain English
A high-severity security flaw in keycloak. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.9% (higher than 59% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS 3.1)7.5High
Exploit odds (30 days)0.9%top 40.8% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Maven | org.keycloak:keycloak-saml-core | 26.6.2 | GHSA-p5mv-gj8j-xqgf |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| keycloak | 0 – before 26.2.160 – before 26.4.120 – before 26.6.2 | |
| Red Hat | Red Hat build of Keycloak 26.2 | see references |
| Red Hat | Red Hat build of Keycloak 26.2 | see references |
| Red Hat | Red Hat build of Keycloak 26.2 | see references |
| Red Hat | Red Hat build of Keycloak 26.2.16 | see references |
| Red Hat | Red Hat build of Keycloak 26.4 | see references |
| Red Hat | Red Hat build of Keycloak 26.4 | see references |
| Red Hat | Red Hat build of Keycloak 26.4 | see references |
| Red Hat | Red Hat build of Keycloak 26.4.12 | see references |
| Red Hat | Red Hat Single Sign-On 7.6.13 | see references |
| Red Hat | Red Hat Single Sign-On 7.6 for RHEL 7 | see references |
| Red Hat | Red Hat Single Sign-On 7.6 for RHEL 8 | see references |
| Red Hat | Red Hat Single Sign-On 7.6 for RHEL 9 | see references |
| Red Hat | RHEL-8 based Middleware Containers | see references |
Weakness: CWE-1286 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
References
- RHSA-2026:19594 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:19595 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:19596 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:19597 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:76128 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:76129 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:76130 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:76132 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:76134 vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/security/cve/CVE-2026-7307 vdb-entry, x_refsource_REDHAT
- RHBZ#2476526 issue-tracking, x_refsource_REDHAT
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-7307.json x_sadp-csaf-vex