How severe is CVE-2023-30589?

CVE-2023-30589 has a CVSS score of 7.5/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2023-30589?

CVE-2023-30589 affects the following packages: llhttp (npm). Ecosystems affected: npm.

How do I fix CVE-2023-30589?

Update llhttp to 8.1.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-30589 is resolved across your whole dependency graph.

How do I detect CVE-2023-30589 in my npm dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for llhttp, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2023-30589 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Is CVE-2023-30589 actively exploited in the wild?

Yes. There are 1 known exploit references for CVE-2023-30589, including 1 in-the-wild exploitation observed on GitHub and other sources. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for CVE-2023-30589?

CVE-2023-30589 has an EPSS (Exploit Prediction Scoring System) score of 3.9%, placing it in the 90th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

When was CVE-2023-30589 published, and has it been updated?

CVE-2023-30589 was published on June 30, 2023 and was last updated on October 28, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

📦

📦 npm

Not in CISA KEV

HIGH severity

CVE-2023-30589 — llhttp

HIGH

CVE-2023-30589 is a high-severity (CVSS 7.5) vulnerability in llhttp. 1 public exploit or proof-of-concept reference is indexed, so weaponization risk is real. A fix is available for llhttp — see the affected versions and patch details below.

llhttp vulnerable to HTTP request smuggling

Also known asBIT-node-2023-30589BIT-node-min-2023-30589GHSA-cggh-pq45-6h9x

Published

Jun 30, 2023

Updated

Oct 28, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

1 known

Exploitation data as of Nov 10, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2023-30589.

EPSS Exploitation Probability

via FIRST.org ↗

3.9%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs90th percentile — riskier than 90% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

1 pkg affected

How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.

1other npm packages depend on this — each one inherits the vulnerability until it's patched upstream

llhttpnpm

43downloads / week

Description

The llhttp parser in the http module in Node v20.2.0 does not strictly use the CRLF sequence to delimit HTTP requests. This can lead to HTTP Request Smuggling (HRS).

The CR character (without LF) is sufficient to delimit HTTP header fields in the llhttp parser. According to RFC7230 section 3, only the CRLF sequence should delimit each header-field. This impacts all Node.js active versions: v16, v18, and, v20

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`llhttp`	all versions	8.1.1`npm install llhttp@8.1.1`

Affected Products

2 products · 5 configurations

fedorafedoraproject

2 versions

3738

Application

node.jsnodejs

≥ 20.0.0 && < 20.3.1

range

Exploits & PoCs

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

The llhttp parser in the http module in Node v20.2.0 does not strictly u…

hackerone.comNVDJul 2023

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for llhttp, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update llhttp to 8.1.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-30589 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Fixing This On Your OS

If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.

Red HatModerate

The vulnerability is in the llhttp parsing not using the CRLF sequence which violates the HTTP/1.1 specification, which mandates CRLF as the delimiter. While this might result in request smuggling, the added complexity of creating a valid malformed delimited request and having it reach the intended target and then…

Product	Fixed in	Advisory
Red Hat Enterprise Linux 8	`nodejs:18-8080020230718130356.63b34585`	RHSA-2023:4536
Red Hat Enterprise Linux 8	`nodejs:16-8080020230718141521.63b34585`	RHSA-2023:4537
Red Hat Enterprise Linux 8.6 Extended Update Support	`nodejs:16-8060020230906023909.ad008a3a`	RHSA-2023:5361
Red Hat Enterprise Linux 9	`nodejs:18-9020020230717125503.rhel9`	RHSA-2023:4330
Red Hat Enterprise Linux 9	`nodejs-1:16.20.1-1.el9_2`	RHSA-2023:4331
Red Hat Enterprise Linux 9.0 Extended Update Support	`nodejs-1:16.20.2-1.el9_0`	RHSA-2023:5533

Frequently Asked Questions

The llhttp parser in the http module in Node v20.2.0 does not strictly use the CRLF sequence to delimit HTTP requests. This can lead to HTTP Request Smuggling (HRS). The CR character (without LF) is sufficient to delimit HTTP header fields in the llhttp parser. According to RFC7230 section 3, only the CRLF sequence should delimit each header-field. This impacts all Node.js active versions: v16, v18, and, v20

O3 Security · Impact-Aware SCA

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