Red HatCVE-2026-18212
SAML Redirect Binding implementation of Keycloak: denial of service
No fix yet
A flaw was found in the SAML Redirect Binding implementation of Keycloak, an open-source identity and access management solution. The issue occurs because the custom DEFLATE compression and decompression helpers fail to release native zlib memory after use. An unauthenticated attacker can exploit this by sending repeated malformed SAML requests, leading to native memory exhaustion and a denial of service.
Affected versions
| Package | Affected | Fixed in |
|---|---|---|
| Red Hat Data Grid 8 Product | all versions | No fix yet |
| Red Hat build of Keycloak 26.4.16 Product | all versions | No fix yet |
| all versions | No fix yet | |
| Red Hat build of Keycloak 26.6.7 Product | all versions | No fix yet |
| all versions | No fix yet | |
| all versions | No fix yet |
Details and references
- CVSS 3.1
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- Severity from
- the vendor (its own CVE record or advisory)
- Weakness
- CWE-401
- www.cve.org/CVERecord?id=CVE-2026-18212
- nvd.nist.gov/vuln/detail/CVE-2026-18212
- access.redhat.com/errata/RHSA-2026:68276
- access.redhat.com/errata/RHSA-2026:68277
- access.redhat.com/errata/RHSA-2026:68278
- access.redhat.com/errata/RHSA-2026:68280
- access.redhat.com/security/cve/CVE-2026-18212
- bugzilla.redhat.com/show_bug.cgi?id=2508307