Deno RuntimeApplication · Deno
CVE-2023-33966
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedDeno is a runtime for JavaScript and TypeScript. In deno 1.34.0 and deno_runtime 0.114.0, outbound HTTP requests made using the built-in `node:http` or `node:https` modules are incorrectly not checked against the network permission allow list (`--allow-net`). Dependencies relying on these built-in modules are subject to the vulnerability too. Users of Deno versions prior to 1.34.0 are unaffected. Deno Deploy users are unaffected. This problem has been patched in Deno v1.34.1 and deno_runtime 0.114.1 and all users are recommended to update to this version. No workaround is available for this issue.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceOutbound HTTP requests using Deno's built-in `node:http` and `node:https` modules bypass the network permission allow list (`--allow-net`), allowing network access even when explicitly restricted. This permission bypass affects any code using these modules, including dependencies.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data
Deno RuntimeApplication
= 0.114.0= 1.34.0CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Check installed Deno versionRun `deno --version` and note the version number in the output (e.g., Deno 1.34.0)Affected if The version shown is exactly 1.34.0 or the runtime version is 0.114.0
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Identify node:http or node:https usageSearch your codebase for import statements containing `node:http` or `node:https`, such as `import * as http from "node:http"` or `import https from "node:https"`Affected if Your code or any dependency imports and uses these modules to make outbound HTTP/HTTPS requests
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Verify --allow-net permission is enforcedReview your Deno execution command or configuration for the presence of `--allow-net` flag (with or without specific host allowances)Affected if You rely on `--allow-net` to restrict network access and expect it to block outbound requests from node:http/node:https modules
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Confirm network access occurred without permissionIf you have logging or network monitoring, check if outbound connections were made when `--allow-net` was set to deny or restrict specific hostsAffected if Outbound HTTP/HTTPS requests succeeded despite --allow-net being absent or set to deny
You are affected if you use Deno 1.34.0 (deno_runtime 0.114.0) and your code or dependencies use node:http or node:https modules while depending on --allow-net to control network access.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scopedUpgrade Deno to version 1.34.1 or later (deno_runtime 0.114.1 or later). No workaround exists; restricting network access via `--allow-net` was ineffective for these modules in affected versions.
Deno v1.34.1 / deno_runtime 0.114.1
- Upgrade Deno to version 1.34.1 or higher by running: `deno upgrade`
- If using Deno Runtime (deno_runtime), upgrade to version 0.114.1 or higher
- After upgrading, verify the fix by testing that `node:http` and `node:https` modules now properly respect the `--allow-net` permission flag
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Deno Runtime
Scoped from the published advisory
- Consultation2.0 h
- Implementation1.0 h
- Testing2.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,696.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2023-33966 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2023-33966 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
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