GHSA-xv6h-r36f-3gp5 BIT-keycloak-2026-2575 CVE-2026-2575
Keycloak: Denial of Service due to excessive SAMLRequest decompression
- Severity
- 5.3 / 10
- Medium · CVSS 3.1
- Exploit chance (EPSS)
- 0.65%
- Chance of exploitation in the next 30 days. Higher than 51.08% of scored vulnerabilities.
- Known exploited
- No
- Not in CISA's catalog
- Weakness
- CWE-409 Improper Handling of Highly Compressed Data (Data Amplification)
- Fix
- Available
- 3 packages have a fixed version
Description
A flaw was found in Keycloak. An unauthenticated remote attacker can trigger an application level Denial of Service (DoS) by sending a highly compressed SAMLRequest through the SAML Redirect Binding. The server fails to enforce size limits during DEFLATE decompression, leading to an OutOfMemoryError (OOM) and subsequent process termination. This vulnerability allows an attacker to disrupt the availability of the service.
Affected versions
Maven
| Package | Vulnerable | Fixed in |
|---|---|---|
| org.keycloak:keycloak-saml-adapter-core | < 26.5.4 |
26.5.4 |
| org.keycloak:keycloak-saml-core | < 26.5.4 |
26.5.4 |
| org.keycloak:keycloak-services | < 26.5.4 |
26.5.4 |
How to fix
Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.
org.keycloak:keycloak-saml-adapter-core Maven → 26.5.4
- maven
<dependency><groupId>org.keycloak</groupId><artifactId>keycloak-saml-adapter-core</artifactId><version>26.5.4</version></dependency>- gradle
implementation("org.keycloak:keycloak-saml-adapter-core:26.5.4")
org.keycloak:keycloak-saml-core Maven → 26.5.4
- maven
<dependency><groupId>org.keycloak</groupId><artifactId>keycloak-saml-core</artifactId><version>26.5.4</version></dependency>- gradle
implementation("org.keycloak:keycloak-saml-core:26.5.4")
org.keycloak:keycloak-services Maven → 26.5.4
- maven
<dependency><groupId>org.keycloak</groupId><artifactId>keycloak-services</artifactId><version>26.5.4</version></dependency>- gradle
implementation("org.keycloak:keycloak-services:26.5.4")
Severity breakdown
CVSS 3.1 5.3
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- Low
Weakness
CWE-409: Improper Handling of Highly Compressed Data (Data Amplification)
The product does not handle or incorrectly handles a compressed input with a very high compression ratio that produces a large output.
References
Advisories
Packages
Other links
- github.com/keycloak/keycloak/issues/46372
- github.com/keycloak/keycloak/commit/4f90ef67f698dfb45df0d2f4981271a7c8b47f04
- access.redhat.com/errata/RHSA-2026:3947
- access.redhat.com/errata/RHSA-2026:3948
- access.redhat.com/errata/RHSA-2026:76128
- access.redhat.com/errata/RHSA-2026:76129
- access.redhat.com/errata/RHSA-2026:76130
- access.redhat.com/errata/RHSA-2026:76132
- access.redhat.com/errata/RHSA-2026:76134
- access.redhat.com/security/cve/CVE-2026-2575
- bugzilla.redhat.com/show_bug.cgi
Timeline
- Published
- Last updated by the source
- Latest EPSS score
Related advisories
| Advisory | Severity | Why it's related |
|---|---|---|
| GHSA-v3f7-2p4r-mwfw Keycloak vulnerable to cross-site scripting (xss) via case-insensitive uri validation bypass | High | Also affects org.keycloak:keycloak-services |
| GHSA-9jrw-8xf7-xqhq Keycloak vulnerable to information disclosure through arbitrary filesystem path probing | Medium | Also affects org.keycloak:keycloak-services |
| GHSA-w3p3-7cjg-vgfw Keycloak allows unauthorized access to resources via uma permission ticket bypass | Medium | Also affects org.keycloak:keycloak-services |
| GHSA-f5p5-6xmx-p252 Keycloak vulnerable to authorization bypass via incorrect uri comparison | High | Also affects org.keycloak:keycloak-services |
| GHSA-r7rc-c989-86g6 Keycloak: Attacker can re-enable and take over disabled clients via registration access token | Medium | Also affects org.keycloak:keycloak-services |
| GHSA-4gv3-mc9p-5wqc Keycloak: Unauthenticated account takeover via reset-credentials flow bypass | Critical | Also affects org.keycloak:keycloak-services |
| GHSA-6g26-7cx5-mrrg Keycloak: Information disclosure due to user profile permission bypass | Low | Also affects org.keycloak:keycloak-services |
| GHSA-cpf7-j4cf-vqx4 Keycloak has an Out-of-bounds Read | Medium | Also affects org.keycloak:keycloak-services |
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