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UK Cyber Defence
VulnerabilityAwaiting Analysis

CVE-2026-18212

An unauthenticated attacker can exploit this by sending repeated malformed SAML requests, leading to native memory exhaustion and a denial of service.

HIGH 7.5EPSS 0.70%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.70%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

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 3.1
7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS
0.70% probability · 53th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-401
Source
secalert@redhat.com
EPSS trend
0%3%5%26 October 2026: 0.70%26 October 202626 October 2026

EPSS 0.7% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.