CVE-2026-56223Public exploitNetwork attack vector

Account takeover via unchecked SSO identity merge

Published Jun 24, 2026 · Updated Jun 24, 2026

Improper authentication in Capgo before 12.128.2 allows remote authenticated users to take over accounts through cross-domain SSO. The provision-user merge path transfers SSO identities and deletes duplicate accounts after an email match even when provider-domain lookup fails. Enterprise organization admin access and a controlled, active IdP are required; a forged victim email in a signed SAML assertion grants read/write access to the victim's organizations and data.

CVSS severity9.3
Critical
EPSS probability0.40%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper authentication in Capgo before 12.128.2 allows remote authenticated users to take over accounts through cross-domain SSO. The provision-user merge path transfers SSO identities and deletes duplicate accounts after an email match even when provider-domain lookup fails. Enterprise organization admin access and a controlled, active IdP are required; a forged victim email in a signed SAML assertion grants read/write access to the victim's organizations and data.

The record

CVE
CVE-2026-56223
Published
Jun 24, 2026
Updated
Jun 24, 2026
Vendor
Capgo
Product
Capgo
Classifications
CWE-287, T1606.002
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Jun 24, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 24, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <12.128.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

Capgo · Capgoversion=0 <12.128.2

Published CVSS scores

9.3VulnCheckCVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:N/SC:H/SI:H/SA:N
8.7Cap-goCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesadmin
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-287Improper Authentication
T1606.002Forge Web Credentials: SAML Tokens

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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