# CVE-2026-56249: Capgo - Unauthorized Channel Overwrite and Ownership Takeover via POST /channel Name Collision

> Authenticated users can overwrite existing channels and steal ownership due to flawed validation logic in the channel creation endpoint.

- **Severity:** High 7.2 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:H/VA:L/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 30 Jun 2026
- **Updated:** 1 Jul 2026
- **Also known as:** GHSA-644f-gvrf-jgw7, GHSA-vj24-j594-3wv3

## What is CVE-2026-56249?

CVE-2026-56249 is a high-severity missing authorization vulnerability in Capgo, published on 30 Jun 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Capgo before 12.128.2 contains an authorization bypass vulnerability in the channel creation endpoint that allows authenticated users to overwrite existing channels by reusing their names. Attackers with app.create_channel permission can exploit a logic mismatch between existence validation and upsert operations to reassign channel ownership and modify critical production channel configurations.

Weakness: CWE-285 (Improper Authorization)

## Which versions are affected by CVE-2026-56249?


## How do I fix CVE-2026-56249?

No fix has been published for CVE-2026-56249 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-56249 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-56249 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-56249 and fix it if it is affected.

What it is: CVE-2026-56249 is a high-severity missing authorization vulnerability in Capgo, published on 30 Jun 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-56249 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-2026-56249/ (Markdown: https://insights.sbomify.com/CVE-2026-56249/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-56249
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-56249
- OSV: https://osv.dev/vulnerability/CVE-2026-56249

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-56249/
Summaries are generated and may contain mistakes; the official description above is the record.