4.3

CVE-2026-9798: redhat build_of_keycloak

CVSS: 4.3v3.1MediumModified
AliasesCGA-455m-8j85-4chfCGA-4c29-xrxf-hm4vCGA-579v-rf2f-m86q
Published 28-05-2026Last modified 20-08-2026
Open JSON

Vulnerability summary

CVE-2026-9798 is a medium (CVSS 4.3) vulnerability in redhat build_of_keycloak. EPSS estimates a 0.49% chance of exploitation in the next 30 days, higher than 41.1% of scored vulnerabilities.

Overall risk
17/100
0100
Low · default modelHow is this calculated?
CVSS score
4.3/10
010
Medium · v3.1 (CVE.org)
EPSS score
0.49%
0%100%
Low · +0.14 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 0 · Related 1
CGA-XXVH-H973-XJ3X

Timeline

  1. 28-05-2026
    PublishedVulnerability first disclosed.
  2. 20-08-2026
    Last modifiedVulnerability information updated.

Description

A flaw was found in Keycloak, an open-source identity and access management solution. When a user account is temporarily locked due to repeated failed login attempts, an attacker with valid client credentials can exploit the Client-Initiated Backchannel Authentication (CIBA) flow to bypass this brute-force protection. This allows continued authentication attempts and token issuance even when the account should be locked, potentially enabling further unauthorized access attempts.

CVSS metrics

5 scores · 5 sources · 1 version

EPSS trend

Probability

0.49%

Chance of exploitation in the next 30 days

Percentile

41%

Versus all other CVEs

30-day change

+0.14 pp

From 0.35% on 21-09-2026

21-09-202621-10-2026
EPSS score
0.49%

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

Chainguard18 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-26.6< 26.6.6-r0
Wolfi6 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-26.6< 26.6.6-r0
Org.keycloak1 product
  • keycloak-services≤ 26.4.7 | ≥ 26.5.0, ≤ 26.6.4
Redhat1 product

4 vendors · 26 products

References

15 links
Show all 15 references