Blockchain: Missing Authentication for Critical Functionality
CVE-2026-3194 is a high-severity missing authentication for critical functionality vulnerability in Blockchain from Chia, with a CVSS 3.1 base score of 7.0 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. Affected Blockchain versions: 2.1.0. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.27% 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 Blockchain you run against the affected versions below, and install the vendor's latest release.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Chia | Blockchain | 2.1.0 | Not stated |
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
- LocalThe attacker needs local access or must trick a user into running something.
- Attack complexity
- HighSuccess depends on conditions outside the attacker's control.
- 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
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 1.1 | Low | CNA (vuldb.com) |
| CVSS 3.1 | 4.5 | Medium | CNA (vuldb.com) |
| CVSS 3.1 | 7.0 | High | NVD |
| CVSS 2.0 | 3.5 | Low | CNA (vuldb.com) |
Official description
A flaw has been found in Chia Blockchain 2.1.0. The affected element is the function send_transaction/get_private_key of the component RPC Server Master Passphrase Handler. This manipulation causes missing authentication. The attack can only be executed locally. The attack's complexity is rated as high. The exploitability is described as difficult. The exploit has been published and may be used. The vendor was informed early via email. A separate report via bugbounty was rejected with the reason "This is by design. The user is responsible for host security".
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Missing Authentication for Critical Functionality
The product does not perform any authentication for functionality that requires a provable user identity or consumes a significant amount of resources.
How developers prevent this class of flaw
- For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.
- Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, consider using libraries with authentication capabilities such as OpenSSL or the ESAPI Authenticator.
- When storing data in the cloud (e.g., S3 buckets, Azure blobs, Google Cloud Storage, etc.), use the provider's controls to require strong authentication for users who should be allowed to access the data.
More Missing Authentication for Critical Functionality vulnerabilities (CWE-306)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Third-party and government advisories
- vuldb.com/?id.347750Third Party Advisory, VDB Entry
- vuldb.com/?submit.757201Third Party Advisory, VDB Entry
Technical write-ups (may include proof of concept)
- github.com/Danimlzg/chia-rpc-auth-bypass.gitExploit, Third Party Advisory
Other references
- vuldb.com/?ctiid.347750Permissions Required, VDB Entry
Other vulnerabilities in Blockchain
- 8.1 High severity
Recent Missing Authentication for Critical Functionality vulnerabilities
- 9.8 Critical severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 9.8 Critical severity
- 9.8 Critical severity
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