4.9

CVE-2026-9801: redhat build_of_keycloak

CVSS: 4.9v3.1MediumModified
AliasesCGA-5557-qwq2-pfq2CGA-892q-3ppw-8gr7CGA-98fg-x83c-q52h
Published 28-05-2026Last modified 26-06-2026
Open JSON

Vulnerability summary

CVE-2026-9801 is a medium (CVSS 4.9) vulnerability in redhat build_of_keycloak. EPSS estimates a 0.90% chance of exploitation in the next 30 days, higher than 58.8% of scored vulnerabilities.

Overall risk
20/100
0100
Low · default modelHow is this calculated?
CVSS score
4.9/10
010
Medium · v3.1 (CVE.org)
EPSS score
0.90%
0%100%
Low · +0.42 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 28-05-2026
    PublishedVulnerability first disclosed.
  2. 26-06-2026
    Last modifiedVulnerability information updated.

Description

A flaw was found in Keycloak. A remote attacker with high privileges, such as a realm administrator configuring a malicious Lightweight Directory Access Protocol (LDAP) server or an attacker compromising an upstream LDAP server, could exploit this vulnerability. By sending a malformed LDAP password policy response during a password authentication request, the attacker can trigger an OutOfMemoryError. This causes the Keycloak Java Virtual Machine (JVM) to terminate, leading to a denial of service (DoS) for all realms on the affected node.

CVSS metrics

5 scores · 5 sources · 1 version

EPSS trend

Probability

0.90%

Chance of exploitation in the next 30 days

Percentile

59%

Versus all other CVEs

30-day change

+0.42 pp

From 0.48% on 18-09-2026

18-09-202618-10-2026
EPSS score
0.90%

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-26.4All versions (No fix recorded)
  • keycloak-26.4-iamguarded-compatAll versions (No fix recorded)
  • keycloak-26.5All versions (No fix recorded)
  • keycloak-26.5-iamguarded-compatAll versions (No fix recorded)
  • keycloak-fips-26.4All versions (No fix recorded)
Wolfi4 products
  • keycloak-26.4All versions (No fix recorded)
  • keycloak-26.4-iamguarded-compatAll versions (No fix recorded)
  • keycloak-26.5All versions (No fix recorded)
  • keycloak-26.5-iamguarded-compatAll versions (No fix recorded)
Org.keycloak1 product
  • keycloak-ldap-federation< 26.6.3
Redhat1 product

4 vendors · 18 products

References

11 links
Show all 11 references