CVE-2026-18212Keycloak-services: keycloak-services: saml redirect deflate helpers leak native zlib state
Updated under an hour ago ()
Does this affect you?
It affects Red Hat build of Keycloak 26.4 and 3 other products. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
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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.
- CVSS
- 7.5 HIGH (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- Weakness (CWE)
- CWE-401
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- redhat
- NVD analysis
- Awaiting Analysis
- Record last updated
- Sep 16, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Red Hat Red Hat build of Keycloak 26.4 redhat:build_keycloak | from 26.4.16-2 not affected | CNA record |
Red Hat Red Hat Data Grid 8 redhat:jboss_data_grid | 8 | CNA record |
Red Hat Red Hat JBoss Enterprise Application Platform Expansion Pack redhat:jbosseapxp | Versions not stated | CNA record |
Red Hat Red Hat Single Sign-On 7 redhat:red_hat_single_sign_on | 7 | CNA record |
References
- https://access.redhat.com/errata/RHSA-2026:68276vendor-advisory, x-refsource-redhat
- https://access.redhat.com/errata/RHSA-2026:68277vendor-advisory, x-refsource-redhat
- https://access.redhat.com/errata/RHSA-2026:68278vendor-advisory, x-refsource-redhat
- https://access.redhat.com/errata/RHSA-2026:68280vendor-advisory, x-refsource-redhat
- https://access.redhat.com/security/cve/CVE-2026-18212vdb-entry, x-refsource-redhat
- https://bugzilla.redhat.com/show_bug.cgi?id=2508307issue-tracking, x-refsource-redhat
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.