4.8

CVE-2026-56666: zitadel Improper Authentication

CVSS: 4.8v3.1MediumDeferred
AliasesGHSA-992q-9gwp-7r79GO-2026-6470CGA-f4p5-7jwm-4p47
Published 10-07-2026Last modified 13-07-2026
Open JSON

Vulnerability summary

CVE-2026-56666 is a medium (CVSS 4.8) Improper Authentication vulnerability in zitadel. EPSS estimates a 0.29% chance of exploitation in the next 30 days, higher than 19.6% of scored vulnerabilities.

Overall risk
19/100
0100
Low · default modelHow is this calculated?
CVSS score
4.8/10
010
Medium · v3.1 (CVE.org)
EPSS score
0.29%
0%100%
Low · 0.00 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 3
OPENSUSE-SU-2026:21897-1SUSE-SU-2026:23855-1SUSE-SU-2026:23863-1

Timeline

  1. 10-07-2026
    PublishedVulnerability first disclosed.
  2. 13-07-2026
    Last modifiedVulnerability information updated.

Description

ZITADEL is an open source identity management platform. Prior to 4.15.3, ZITADEL's external identity provider handler checks that the local user's email is verified but does not verify that the external IdP confirmed ownership of the same email before auto-linking by email, allowing a permissive provider account with a victim email address to be linked to the victim's local account. This issue is fixed in version 4.15.3.

CVSS metrics

4 scores · 4 sources · 1 version

EPSS trend

Probability

0.29%

Chance of exploitation in the next 30 days

Percentile

20%

Versus all other CVEs

30-day change

0.00 pp

From 0.29% on 18-09-2026

18-09-202618-10-2026
EPSS score
0.29%

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

Chainguard1 product
  • zitadel-3All versions (No fix recorded)
Github.com/zitadel1 product
  • zitadel< 4.15.3 | All versions (No fix recorded)
Zitadel1 product

3 vendors · 3 products

References

6 links