CVE-2026-45071: Symfony DomCrawler XXE in addXmlContent

CVE-2026-45071 · Severity: medium · CVSS 4 · Published 2026-07-14

Symfony is a popular PHP framework used to build web applications. A vulnerability in its DomCrawler component could allow an attacker to read sensitive files from the server's local storage by submitting specially crafted XML data. This could lead to the exposure of configuration files, credentials, or other private system information.

Technologies: symfony/symfony (Packagist). Vendors: Packagist, Symfony.

Quick answers

Is CVE-2026-45071 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-45071 being exploited in the wild.
How severe is CVE-2026-45071?
Medium severity, with a CVSS score of 4, published 14 July 2026.
Which products and versions are affected?
symfony/dom-crawler (Packagist) ECOSYSTEM:introduced=0,fixed=5.4.52; symfony/symfony (Packagist) ECOSYSTEM:introduced=0,fixed=5.4.52; Symfony DomCrawler < 5.4.52, >= 6.0.0, < 6.4.40, >= 7.0.0, < 7.4.12, >= 8.0.0, < 8.0.12.
Is there a fix for CVE-2026-45071?
Yes. symfony/dom-crawler (Packagist): upgrade to 5.4.52 or later; symfony/symfony (Packagist): upgrade to 5.4.52 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-45071 attacked?
It is attacked over the network, in a software library.
Am I affected by CVE-2026-45071?
Check whether you run symfony/dom-crawler (Packagist), symfony/symfony (Packagist) or Symfony DomCrawler at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • symfony/dom-crawler (Packagist): upgrade to 5.4.52 or later
    composer require symfony/dom-crawler:^5.4.52
  • symfony/symfony (Packagist): upgrade to 5.4.52 or later
    composer require symfony/symfony:^5.4.52

Technical details

An XML External Entity (XXE) vulnerability exists in the Symfony DomCrawler component's Crawler::addXmlContent() method. The root cause is that the method explicitly sets DOMDocument::$validateOnParse to true before calling loadXML(), which re-enables external entity resolution even if it was otherwise disabled. A remote, unauthenticated attacker can exploit this by providing malicious XML content containing file:// entities, leading to arbitrary local file disclosure. The issue is resolved in versions 5.4.52, 6.4.40, 7.4.12, and 8.0.12 by removing the problematic property assignment.

Affected products

  • Symfony symfony/symfony < 5.4.52, >= 6.0.0-BETA1 < 6.4.40, >= 7.0.0-BETA1 < 7.4.12, >= 8.0.0-BETA1 < 8.0.12
  • Symfony symfony/dom-crawler < 5.4.52, >= 6.0.0-BETA1 < 6.4.40, >= 7.0.0-BETA1 < 7.4.12, >= 8.0.0-BETA1 < 8.0.12

Identifiers

  • CVE-2026-45071
  • GHSA-x6g4-fwcc-jj8w

Timeline

  • 2026-05-20: patched: Security releases 5.4.52, 6.4.40, 7.4.12, and 8.0.12 published.
  • 2026-07-14: disclosed: CVE-2026-45071 published.

References

This page as Markdown. Free to reuse under CC BY 4.0 with a link back.