# CVE-2026-100621: capgo.app Content-Lock Bypass via r2-direct Bundle Mutation

> Attackers with API keys can bypass content locks to modify OTA bundle metadata, serving altered updates to devices.

- **Severity:** Medium 5.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/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:** 26 Sep 2026
- **Updated:** 30 Sep 2026
- **Also known as:** GHSA-7957-wr5g-x2vr

## What is CVE-2026-100621?

CVE-2026-100621 is a medium-severity missing authorization vulnerability in Cap-go capgo.app, published on 26 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Capgo (capgo.app) contains an incomplete access-control/content-lock enforcement issue affecting all versions; no patch is available at the time of publication. The `enforce_encrypted_bundle_trigger` / `check_encrypted_bundle_on_insert` content lock in supabase/schemas/prod.sql exempts `app_versions` rows whose previous `storage_provider` is `r2-direct`, so delivery-critical columns (name, app_id, session_key, key_id, storage_provider, r2_path, external_url, checksum, manifest, native_packages) remain mutable while a row is in that state. Separately, the channel/version join used by the `/updates` endpoint (supabase/functions/_backend/utils/pg.ts) filters only deleted versions and does not exclude `r2-direct` versions, so such rows remain OTA-selectable. An attacker holding a Capgo API key with bundle write/upload permission can create or keep a bundle version in the `r2-direct` state, assign it to a channel, and then modify these fields via direct PostgREST requests, causing altered bundle metadata (for example checksum and session_key) to be served to devices through `/updates`. This bypasses the post-upload content immutability hardening added for a previous app_versions metadata-tampering issue.

Weakness: CWE-284 (Improper Access Control)

## Which versions are affected by CVE-2026-100621?


## How do I fix CVE-2026-100621?

No fix has been published for CVE-2026-100621 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-100621 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-100621 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-100621 and fix it if it is affected.

What it is: CVE-2026-100621 is a medium-severity missing authorization vulnerability in Cap-go capgo.app, published on 26 Sep 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-2026-100621 exists.

Affected product: Cap-go capgo.app. 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-2026-100621/ (Markdown: https://insights.sbomify.com/CVE-2026-100621/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-100621
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-100621
- OSV: https://osv.dev/vulnerability/CVE-2026-100621

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-100621/
Summaries are generated and may contain mistakes; the official description above is the record.