🛡️ CVE-2026-18217 — build-of-keycloak

🟢 CVSS 3.4 — Low ✅ No Known Exploit CWE-20 NVD
3.4
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

A flaw was found in the SAML protocol implementation of Keycloak, an open-source identity and access management solution. The issue occurs when Keycloak handles SAML authentication requests using the HTTP-Redirect binding. If a client is configured with a wildcard redirect URL, an attacker can craft a request that includes malicious parameters. When a user authenticates, Keycloak appends its legitimate response to the attacker's parameters. This can cause some service providers to process the attacker's data instead of the real login information, potentially leading to a user being logged into the wrong account.

How this vulnerability can be exploited

This issue can be reached over the network, attack complexity is high, an attacker needs no privileges on the target. A user must be tricked into taking some action. The scope is changed, meaning a successful attack can affect components beyond the vulnerable one. Rated impact: confidentiality none, integrity low, availability none.

Weakness class

CVE-2026-18217 is classified as CWE-20: Improper Input Validation. The application accepts input without checking that it has the expected form, so malformed values reach code that assumes they are well formed.

Affected software

CVE-2026-18217 is recorded against 1 package.

  • build-of-keycloak

Timeline and source

Published on 31 July 2026 and last revised on 7 August 2026. No public exploit is currently recorded for this entry. Record sourced from NVD.

References

access.redhat.com
bugzilla.redhat.com

Details

Severity LOW
CVSS Score 3.4
CVSS Vector CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:N/I:L/A:N
CWE CWE-20
Public Exploit ✅ No
Source NVD
Published 2026-07-31
Updated 2026-08-11
Modified 2026-08-07
Fix URL N/A

Affected Packages

Software From version Fixed in
build-of-keycloak — —

Similar Threats

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