deepseek-harness: Missing Authentication for Critical Functionality
CVE-2026-82033 is a high-severity missing authentication for critical functionality vulnerability in deepseek-harness from Deepseek-ai, with a CVSS 3.1 base score of 8.4 out of 10. It can be exploited with local access to the system by an unauthenticated attacker, without any action from a user. The record lists version 0.1.2-alpha.2 as the first without the flaw, so updating deepseek-harness to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.22% 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 deepseek-harness to 0.1.2-alpha.2 or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Deepseek-ai | deepseek-harness | before 0.1.2-alpha.2; 3e24087bfaeabe40b58ba2f7b936895b8f93fe27 and earlier | 0.1.2-alpha.2 |
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
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- 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:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by CNA (vulncheck.com).
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 8.6 | High | CNA (vulncheck.com) |
| CVSS 3.1 | 8.4 | High | CNA (vulncheck.com) |
Official description
DeepSeek Harness prior to 0.1.2-alpha.2, and specifically commit 3e24087, contains a missing authentication vulnerability in its web profile HTTP and WebSocket RPC control plane, allowing any local process, including those running as a different OS user, to reach unauthenticated session methods such as session.create and session.prompt. Attackers can invoke session.prompt to trigger the agent's bash and filesystem tools, achieve arbitrary command execution as the victim user using their configured model credentials, intercept live session traffic and logs over the event mux stream, and bypass human tool-approval checks via POST /api/respond by matching only rpcId, approvalId, and sessionId values broadcast over the ungated stream.
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: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Recent Missing Authentication for Critical Functionality vulnerabilities
- 8.5 High severity
- 8.3 High severity
- 8.1 High severity
- 8.8 High severity
- 9.8 Critical severity
- 9.8 Critical severity
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