# CVE-2026-56223: Capgo - Account Takeover via Cross-Domain SSO Email Assertion in provision-user

> Attackers can take over victim accounts by forging SAML assertions in the provision-user endpoint due to missing domain validation.

- **Severity:** Critical 9.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:N/SC:H/SI:H/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 24 Jun 2026
- **Updated:** 17 Sep 2026
- **Also known as:** GHSA-jhjh-vp9p-54fg

## What is CVE-2026-56223?

CVE-2026-56223 is a critical authentication bypass vulnerability in Capgo, published on 24 Jun 2026. An attacker needs administrator access to exploit it, with no action from the victim.

### Official description

Capgo before 12.128.2 contains a cross-domain SSO account takeover vulnerability in the provision-user endpoint that allows attackers to merge arbitrary victim accounts based on email match without validating SSO provider domain authorization. An attacker with enterprise org admin access and a malicious IdP can forge SAML assertions containing victim email addresses to trigger account merge and gain full access to victim accounts, organizations, and data.

Weakness: CWE-287 (Improper Authentication)

## Which versions are affected by CVE-2026-56223?


## How do I fix CVE-2026-56223?

No fix has been published for CVE-2026-56223 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-56223 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-56223 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-56223 and fix it if it is affected.

What it is: CVE-2026-56223 is a critical authentication bypass vulnerability in Capgo, published on 24 Jun 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-56223 exists.

Affected product: Capgo. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-56223/ (Markdown: https://insights.sbomify.com/CVE-2026-56223/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-56223
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-56223
- OSV: https://osv.dev/vulnerability/CVE-2026-56223

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-56223/
Summaries are generated and may contain mistakes; the official description above is the record.