Red Hat KeyCloak SAMLRequest data amplification

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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5.3$0-$5k0.00

Summaryinfo

A vulnerability classified as problematic has been found in Red Hat KeyCloak. This affects an unknown function of the component SAMLRequest. This manipulation causes data amplification. The identification of this vulnerability is CVE-2026-2575. It is possible to initiate the attack remotely. There is no exploit available.

Detailsinfo

A vulnerability classified as problematic was found in Red Hat KeyCloak (version now known). Affected by this vulnerability is some unknown processing of the component SAMLRequest. The manipulation with an unknown input leads to a data amplification vulnerability. The CWE definition for the vulnerability is CWE-409. The product does not handle or incorrectly handles a compressed input with a very high compression ratio that produces a large output. As an impact it is known to affect availability. The summary by CVE is:

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.

The advisory is shared at access.redhat.com. This vulnerability is known as CVE-2026-2575 since 02/16/2026. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 03/22/2026). MITRE ATT&CK project uses the attack technique T1499 for this issue.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the databases at EUVD (EUVD-2026-12766) and CERT Bund (WID-SEC-2026-0416). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Affected

  • Red Hat Enterprise Linux
  • Open Source Keycloak

Productinfo

Vendor

Name

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.3
VulDB Meta Temp Score: 5.3

VulDB Base Score: 5.3
VulDB Temp Score: 5.3
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 5.3
CNA Vector (redhat): 🔒

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Data amplification
CWE: CWE-409 / CWE-404
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔒

Timelineinfo

02/16/2026 CVE reserved
03/18/2026 +30 days Advisory disclosed
03/18/2026 +0 days VulDB entry created
03/22/2026 +4 days VulDB entry last update

Sourcesinfo

Vendor: redhat.com

Advisory: RHSA-2026:3947
Status: Confirmed

CVE: CVE-2026-2575 (🔒)
GCVE (CVE): GCVE-0-2026-2575
GCVE (VulDB): GCVE-100-351469
EUVD: 🔒
CERT Bund: WID-SEC-2026-0416 - Keycloak: Schwachstelle ermöglicht Denial of Service

Entryinfo

Created: 03/18/2026 07:02
Updated: 03/22/2026 03:28
Changes: 03/18/2026 07:02 (61), 03/18/2026 11:42 (1), 03/18/2026 19:29 (7), 03/22/2026 03:28 (1)
Complete: 🔍
Cache ID: 216::103

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Discussion

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