How severe is CVE-2023-45133?

CVE-2023-45133 has a CVSS score of 9.3/10, rated CRITICAL. Immediate patching is strongly recommended.

Which packages are affected by CVE-2023-45133?

CVE-2023-45133 affects the following packages: @babel/traverse (npm), @babel/traverse (npm), babel-traverse (npm). Ecosystems affected: npm.

How do I fix CVE-2023-45133?

Update @babel/traverse to 7.23.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-45133 is resolved across your whole dependency graph.

How do I detect CVE-2023-45133 in my npm dependencies?

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

How do I mitigate CVE-2023-45133 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-2023-45133 actively exploited in the wild?

No public exploit code has been indexed for CVE-2023-45133 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2023-45133?

CVE-2023-45133 has an EPSS (Exploit Prediction Scoring System) score of 0.5%, placing it in the 45th 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.

What type of vulnerability is CVE-2023-45133?

CVE-2023-45133 is classified as CWE-184 (CWE-184), CWE-697 (CWE-697). These weakness types describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2023-45133 published, and has it been updated?

CVE-2023-45133 was published on October 12, 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

CRITICAL severity

CVE-2023-45133 — @babel/traverse

CRITICALFix: babel/babel@b13376b

CVE-2023-45133 is a critical-severity (CVSS 9.3) CWE-184 vulnerability in @babel/traverse. A fix is available for @babel/traverse — see the affected versions and patch details below.

Babel vulnerable to arbitrary code execution when compiling specifically crafted malicious code

Also known asGHSA-67hx-6x53-jw92

Published

Oct 12, 2023

Updated

Oct 28, 2026

Affected

3 pkgs

Patched

2 / 3

Exploits

None indexed

Exploitation data as of Nov 6, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

A successful exploit gives an attacker total control of the affected component, not partial access.
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-2023-45133.

EPSS Exploitation Probability

via FIRST.org ↗

0.5%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs45th percentile — riskier than 45% 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

3 pkgs 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.

5Kother npm packages depend on this — each one inherits the vulnerability until it's patched upstream

@babel/traversenpm

287.1Mdownloads / week

babel-traversenpm

2.9Mdownloads / week

Description

Impact

Using Babel to compile code that was specifically crafted by an attacker can lead to arbitrary code execution during compilation, when using plugins that rely on the path.evaluate()or path.evaluateTruthy() internal Babel methods.

Known affected plugins are:

@babel/plugin-transform-runtime
@babel/preset-env when using its useBuiltIns option
Any "polyfill provider" plugin that depends on @babel/helper-define-polyfill-provider, such as babel-plugin-polyfill-corejs3, babel-plugin-polyfill-corejs2, babel-plugin-polyfill-es-shims, babel-plugin-polyfill-regenerator

No other plugins under the @babel/ namespace are impacted, but third-party plugins might be.

Users that only compile trusted code are not impacted.

Patches

The vulnerability has been fixed in @babel/[email protected].

Babel 6 does not receive security fixes anymore (see Babel's security policy), hence there is no patch planned for babel-traverse@6.

Workarounds

Upgrade @babel/traverse to v7.23.2 or higher. You can do this by deleting it from your package manager's lockfile and re-installing the dependencies. @babel/core >=7.23.2 will automatically pull in a non-vulnerable version.
If you cannot upgrade @babel/traverse and are using one of the affected packages mentioned above, upgrade them to their latest version to avoid triggering the vulnerable code path in affected @babel/traverse versions:
- @babel/plugin-transform-runtime v7.23.2
- @babel/preset-env v7.23.2
- @babel/helper-define-polyfill-provider v0.4.3
- babel-plugin-polyfill-corejs2 v0.4.6
- babel-plugin-polyfill-corejs3 v0.8.5
- babel-plugin-polyfill-es-shims v0.10.0
- babel-plugin-polyfill-regenerator v0.5.3

Affected Packages

3 total 2 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`@babel/traverse`	all versions	7.23.2`npm install @babel/traverse@7.23.2`
📦npm	`@babel/traverse`	≥ 8.0.0-alpha.0&&< 8.0.0-alpha.4	8.0.0-alpha.4`npm install @babel/traverse@8.0.0-alpha.4`
📦npm	`babel-traverse`	all versions	No fix

Affected Products

9 products · 15 configurations

Application

babelbabeljs

< 7.23.2

1 version

8.0.0

Application

babel-helper-define-polyfill-providerbabeljs

< 0.4.3

range

Application

babel-plugin-polyfill-corejs2babeljs

< 0.4.6

range

Application

babel-plugin-polyfill-corejs3babeljs

< 0.8.5

range

Application

babel-plugin-polyfill-es-shimsbabeljs

< 0.10.0

range

Application

babel-plugin-polyfill-regeneratorbabeljs

< 0.5.3

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @babel/traverse, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update @babel/traverse to 7.23.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-45133 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 HatImportant

Red Hat Satellite does not directly use any affected components, but some of the packages it ships with contain them in the form of a dependency. However, the chances of exploitation are low because the build environment for Satellite is restricted, with limited opportunity for injecting untrusted code. Therefore, the…

Workaround published by Red Hat

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.

Source: Red Hat security advisory for CVE-2023-45133 (CC BY 4.0)

Frequently Asked Questions

### Impact Using Babel to compile code that was specifically crafted by an attacker can lead to arbitrary code execution during compilation, when using plugins that rely on the `path.evaluate()`or `path.evaluateTruthy()` internal Babel methods. Known affected plugins are: - `@babel/plugin-transform-runtime` - `@babel/preset-env` when using its [`useBuiltIns`](https://babeljs.io/docs/babel-preset-env#usebuiltins) option - Any "polyfill provider" plugin that depends on `@babel/helper-define-polyfill-provider`, such as `babel-plugin-polyfill-corejs3`, `babel-plugin-polyfill-corejs2`, `babel-plu