7.5

CVE-2026-4634: redhat build_of_keycloak

CVSS: 7.5v3.1HighModified
AliasesCGA-86gh-x565-wfw3CGA-9956-fgfq-v5m3CGA-j26h-pjh8-8pjx
Published 02-04-2026Last modified 06-10-2026
Open JSON

Vulnerability summary

CVE-2026-4634 is a high (CVSS 7.5) vulnerability in redhat build_of_keycloak. EPSS estimates a 0.86% chance of exploitation in the next 30 days, higher than 57.8% of scored vulnerabilities.

Overall risk
30/100
0100
Medium · default modelHow is this calculated?
CVSS score
7.5/10
010
High · v3.1 (CVE.org)
EPSS score
0.86%
0%100%
Low · +0.34 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 3 · Related 1
RHSA-2026:76128RHSA-2026:76129RHSA-2026:76130CGA-X9JX-4G6W-95RC

Timeline

  1. 02-04-2026
    PublishedVulnerability first disclosed.
  2. 06-10-2026
    Last modifiedVulnerability information updated.

Description

A flaw was found in Keycloak. An unauthenticated attacker can exploit this vulnerability by sending a specially crafted POST request with an excessively long scope parameter to the OpenID Connect (OIDC) token endpoint. This leads to high resource consumption and prolonged processing times, ultimately resulting in a Denial of Service (DoS) for the Keycloak server.

CVSS metrics

5 scores · 5 sources · 1 version

EPSS trend

Probability

0.86%

Chance of exploitation in the next 30 days

Percentile

58%

Versus all other CVEs

30-day change

+0.34 pp

From 0.52% on 19-09-2026

19-09-202619-10-2026
EPSS score
0.86%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Chainguard12 products
  • keycloak-26.3-iamguarded-compatAll versions (No fix recorded)
  • keycloak-26.4All versions (No fix recorded)
  • keycloak-26.4-iamguarded-compatAll versions (No fix recorded)
  • keycloak-26.5< 26.5.7-r0
  • keycloak-26.5-iamguarded-compat< 26.5.7-r0
Wolfi4 products
  • keycloak-26.4All versions (No fix recorded)
  • keycloak-26.4-iamguarded-compatAll versions (No fix recorded)
  • keycloak-26.5< 26.5.7-r0
  • keycloak-26.5-iamguarded-compat< 26.5.7-r0
Org.keycloak1 product
  • keycloak-services< 26.5.7
Redhat1 product

4 vendors · 18 products

References

16 links
Show all 16 references