capgo.app: Authorization Bypass Through User-Controlled Key
CVE-2026-100627 is a high-severity authorization bypass through user-controlled key vulnerability in capgo.app from Cap-go, with a CVSS 3.1 base score of 8.1 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. Affected capgo.app versions: all versions. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.35% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of capgo.app you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on github.com for workarounds and exact fixed builds.
Affected products and versions
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- NoneNo data is disclosed.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H. Scored by CNA (vulncheck.com).
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 7.2 | High | CNA (vulncheck.com) |
| CVSS 3.1 | 8.1 | High | CNA (vulncheck.com) |
Official description
Capgo (Cap-go/capgo.app) server backend Supabase functions contain an incorrect authorization flaw in the API-key bundle promotion path. The PUT /bundle endpoint, available to "all" and "write" API keys, dispatches to setChannel, which authorizes with checkPermission(c, 'channel.promote_bundle', { appId: body.app_id }) and omits the request's channel_id. Because the omitted scope field is passed to rbac_check_permission_direct as SQL NULL, and channel-scope override evaluation is gated on p_channel_id IS NOT NULL, per-channel allow/deny overrides are never evaluated. A principal holding app-level channel.promote_bundle (granted by default to the app_developer and app_uploader roles) can therefore promote a bundle to a channel for which an explicit per-channel deny override exists, updating public.channels.version for the supplied channel_id; the target channel is only validated after authorization. The issue is confirmed on main at commit de66fa51e7ff2f50283cc1455c3d80ab3eb0ae43 and likely earlier versions; no patched version is known at the time of publication.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Authorization Bypass Through User-Controlled Key
The system's authorization functionality does not prevent one user from gaining access to another user's data or record by modifying the key value identifying the data.
How developers prevent this class of flaw
- For each and every data access, ensure that the user has sufficient privilege to access the record that is being requested.
- Make sure that the key that is used in the lookup of a specific user's record is not controllable externally by the user or that any tampering can be detected.
- Use encryption in order to make it more difficult to guess other legitimate values of the key or associate a digital signature with the key so that the server can verify that there has been no tampering.
More Authorization Bypass Through User-Controlled Key vulnerabilities (CWE-639)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Other references
Other vulnerabilities in capgo.app
- 7.1 High severity
- 8.8 High severity
- 7.5 High severity
- 8.8 High severity
- 8.5 High severity
- 8.8 High severity
Recent Authorization Bypass Through User-Controlled Key vulnerabilities
- 8.8 High severity
- 8.8 High severity
- 8.8 High severity
- 7.2 High severity
- 7.5 High severity
- 7.6 High severity
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