How severe is GHSA-x6g4-fwcc-jj8w?

No CVSS score has been assigned to GHSA-x6g4-fwcc-jj8w yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by GHSA-x6g4-fwcc-jj8w?

GHSA-x6g4-fwcc-jj8w affects the following packages: symfony/dom-crawler (Packagist), symfony/symfony (Packagist), symfony/dom-crawler (Packagist), symfony/dom-crawler (Packagist), symfony/dom-crawler (Packagist), symfony/symfony (Packagist), symfony/symfony (Packagist), symfony/symfony (Packagist). Ecosystems affected: Packagist.

How do I fix GHSA-x6g4-fwcc-jj8w?

Update symfony/dom-crawler to 5.4.52 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-x6g4-fwcc-jj8w is resolved across your whole dependency graph.

How do I detect GHSA-x6g4-fwcc-jj8w in my Packagist dependencies?

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

How do I mitigate GHSA-x6g4-fwcc-jj8w 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 GHSA-x6g4-fwcc-jj8w actively exploited in the wild?

No public exploit code has been indexed for GHSA-x6g4-fwcc-jj8w 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 GHSA-x6g4-fwcc-jj8w?

GHSA-x6g4-fwcc-jj8w has an EPSS (Exploit Prediction Scoring System) score of 0.6%, placing it in the 46th 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 GHSA-x6g4-fwcc-jj8w?

GHSA-x6g4-fwcc-jj8w is classified as XML External Entity (XXE) (CWE-611). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was GHSA-x6g4-fwcc-jj8w published, and has it been updated?

GHSA-x6g4-fwcc-jj8w was published on May 27, 2026 and was last updated on September 10, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐘 Packagist

Not in CISA KEV

Symfony has XXE (Local File Disclosure) in DomCrawler::addXmlContent() via validateOnParse = trueGHSA-x6g4-fwcc-jj8w

Fix: symfony/symfony@eea5fd7

GHSA-x6g4-fwcc-jj8w is a XML External Entity (XXE) vulnerability in symfony/dom-crawler. A fix is available for symfony/dom-crawler — see the affected versions and patch details below.

Also known asCVE-2026-45071

Published

May 27, 2026

Updated

Sep 10, 2026

Affected

8 pkgs

Patched

8 / 8

Exploits

None indexed

Exploitation data as of Oct 9, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
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 GHSA-x6g4-fwcc-jj8w.

EPSS Exploitation Probability

via FIRST.org ↗

0.6%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs46th percentile — riskier than 46% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Real-World Exposure

8 pkgs affected

🐘symfony/dom-crawler🐘symfony/symfony🐘symfony/dom-crawler🐘symfony/dom-crawler🐘symfony/dom-crawler🐘symfony/symfony🐘symfony/symfony🐘symfony/symfony

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.

Description

symfony/dom-crawler provides the Crawler class for navigating HTML/XML documents with CSS/XPath selectors; symfony/browser-kit's HttpBrowser uses it to parse fetched pages.

Crawler::addXmlContent() sets DOMDocument::$validateOnParse = true before calling loadXML(). Setting validateOnParse re-enables libxml's DTD subset processing, including external entity resolution, even though LIBXML_NONET is passed. LIBXML_NONET blocks network fetches but not file:// entities. An attacker-supplied XML document with a SYSTEM "file:///etc/passwd" entity is therefore expanded.

Resolution

The Crawler::addXmlContent method does not set the validateOnParse flag anymore.

The patch for this issue is available here for branch 5.4.

Credits

Symfony would like to thank Claude Mythos Preview (via Project Glasswing) for reporting the issue and providing the fix.

Affected Packages

8 total 8 fixed

Ecosystem	Package	Vulnerable range	Fix
🐘Packagist	`symfony/dom-crawler`	all versions	5.4.52`composer require symfony/dom-crawler:^5.4.52`
🐘Packagist	`symfony/symfony`	all versions	5.4.52`composer require symfony/symfony:^5.4.52`
🐘Packagist	`symfony/dom-crawler`	≥ 6.0.0&&< 6.4.40	6.4.40`composer require symfony/dom-crawler:^6.4.40`
🐘Packagist	`symfony/dom-crawler`	≥ 7.0.0&&< 7.4.12	7.4.12`composer require symfony/dom-crawler:^7.4.12`
🐘Packagist	`symfony/dom-crawler`	≥ 8.0.0&&< 8.0.12	8.0.12`composer require symfony/dom-crawler:^8.0.12`
🐘Packagist	`symfony/symfony`	≥ 6.0.0&&< 6.4.40	6.4.40`composer require symfony/symfony:^6.4.40`

Affected Products

1 product · 4 configurations

Application

symfonysensiolabs

≥ 8.0.0 && < 8.0.12

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for symfony/dom-crawler, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update symfony/dom-crawler to 5.4.52 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-x6g4-fwcc-jj8w 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.

Frequently Asked Questions

### Description `symfony/dom-crawler` provides the `Crawler` class for navigating HTML/XML documents with CSS/XPath selectors; `symfony/browser-kit`'s `HttpBrowser` uses it to parse fetched pages. `Crawler::addXmlContent()` sets `DOMDocument::$validateOnParse = true` before calling `loadXML()`. Setting `validateOnParse` re-enables libxml's DTD subset processing, including external entity resolution, even though `LIBXML_NONET` is passed. `LIBXML_NONET` blocks **network** fetches but not `file://` entities. An attacker-supplied XML document with a `SYSTEM "file:///etc/passwd"` entity is theref

O3 Security · Impact-Aware SCA

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Symfony has XXE (Local File Disclosure) in DomCrawler::addXmlContent() via validateOnParse = trueGHSA-x6g4-fwcc-jj8w

Exploitation Status

No confirmed exploitation observed yet

EPSS Exploitation Probability

Real-World Exposure

Description

Description

Resolution

Credits

Affected Packages

Affected Products

Detection & mitigation playbook

Detect

Fix

Workarounds

Frequently Asked Questions

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