Capgo: Authentication Bypass Using an Alternate Path or Channel
CVE-2026-56243 is a high-severity authentication bypass using an alternate path or channel vulnerability in Capgo, 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. The record lists version 12.128.2 as the first without the flaw, so updating Capgo to that release or later removes the exposure. 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
- Update Capgo to 12.128.2 or a later version.
- 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
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- NoneAvailability is not affected.
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N. Scored by CNA (vulncheck.com).
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 8.6 | High | CNA (vulncheck.com) |
| CVSS 3.1 | 8.1 | High | CNA (vulncheck.com) |
Official description
Capgo before 12.128.2 contains a security control bypass vulnerability where the PostgREST/RLS plane accepts plaintext API keys through the capgkey header despite enforce_hashed_api_keys being enabled. Attackers can bypass org-level hashed-key enforcement by sending plaintext API keys directly to the PostgREST/RLS plane to access protected resources.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Authentication Bypass Using an Alternate Path or Channel
The product requires authentication, but the product has an alternate path or channel that does not require authentication.
How developers prevent this class of flaw
- Funnel all access through a single choke point to simplify how users can access a resource. For every access, perform a check to determine if the user has permissions to access the resource.
More Authentication Bypass Using an Alternate Path or Channel vulnerabilities (CWE-288)
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
- 8.1 High severity
- 7.3 High severity
- 8.3 High severity
- 7.5 High severity
- 7.5 High severity
- 8.3 High severity
Recent Authentication Bypass Using an Alternate Path or Channel vulnerabilities
- 10.0 Critical severity
- 10.0 Critical severity
- 10.0 Critical severity
- 8.2 High severity
- 8.1 High severity
- 8.7 High severity
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