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

Symfony has XXE (Local File Disclosure) in DomCrawler::addXmlContent() via validateOnParse = true

High Packagist
Severity
0.0 / 10
High · CVSS 4.0
Exploit chance (EPSS)
0.57%
Chance of exploitation in the next 30 days. Higher than 47.23% of scored vulnerabilities.
Known exploited
No
Not in CISA's catalog
Weakness
CWE-611 Improper Restriction of XML External Entity Reference
Fix
Available
2 packages have a fixed version

Description

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 versions

Packagist

PackageVulnerableFixed in
symfony/dom-crawler
< 5.4.52
5.4.52
symfony/dom-crawler
>= 6.0.0, < 6.4.40
6.4.40
symfony/dom-crawler
>= 7.0.0, < 7.4.12
7.4.12
symfony/dom-crawler
>= 8.0.0, < 8.0.12
8.0.12
symfony/symfony
< 5.4.52
5.4.52
symfony/symfony
>= 6.0.0, < 6.4.40
6.4.40
symfony/symfony
>= 7.0.0, < 7.4.12
7.4.12
symfony/symfony
>= 8.0.0, < 8.0.12
8.0.12

How to fix

Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.

symfony/dom-crawler Packagist → 5.4.52

composer
composer require symfony/dom-crawler:^5.4.52

symfony/symfony Packagist → 5.4.52

composer
composer require symfony/symfony:^5.4.52

Severity breakdown

CVSS 4.0 0.0

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U

Attack vector
Network
Attack complexity
Low
Attack requirements
None
Privileges required
Low
User interaction
None
Confidentiality (vulnerable system)
None
Integrity (vulnerable system)
Low
Availability (vulnerable system)
None
Confidentiality (subsequent systems)
None
Integrity (subsequent systems)
None
Availability (subsequent systems)
None
Exploit maturity
Unreported

CVSS 3.1 7.5

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None

Weakness

CWE-611: Improper Restriction of XML External Entity Reference

The product processes an XML document that can contain XML entities with URIs that resolve to documents outside of the intended sphere of control, causing the product to embed incorrect documents into its output.

How to prevent it
  • Implementation, System Configuration: Many XML parsers and validators can be configured to disable external entity expansion.

References

Timeline

  1. Published
  2. Last updated by the source
  3. Latest EPSS score
AdvisorySeverityWhy it's related
GHSA-2v3c-qxhr-7vpv
Symfony: Unbounded Recursion in the YAML Inline Lexer Lets a Single Document Crash the Process
High Also affects symfony/symfony
GHSA-r925-mgvr-h9cc
Symfony: ReDoS in HeaderUtils::split() Reachable Through the Cache-Control Request Header
High Also affects symfony/symfony
GHSA-h5x3-xfc9-m39h
Symfony: UrlGenerator Dot-Segment Encoding Skips Every Other Chained `../` or `./` → Generated URL Collapses Off-Route Under RFC 3986 Normalization
Medium Also affects symfony/symfony
GHSA-v3wm-qf9p-c549
Symfony: HtmlSanitizer URL Parser Deny Gates Underinclusive: Percent-Encoded BiDi Marks and Unicode Whitespace Bypass Visual-Spoofing Defense
Medium Also affects symfony/symfony
GHSA-rrj9-5q2j-4gvr
Symfony: Mailomat Mailer Webhook Parser Reads the HMAC Algorithm from the Request: Signature Algorithm Downgrade
Medium Also affects symfony/symfony
GHSA-38cx-cq6f-5755
Symfony: IpUtils::PRIVATE_SUBNETS Omits IPv6 Transition Forms (6to4, NAT64, Teredo, IPv4-compatible): SSRF Bypass in NoPrivateNetworkHttpClient
High Also affects symfony/symfony
GHSA-6h46-9jf5-q59x
Symfony: Security Firewall Bypass via failure_forward Subrequest: Unauthenticated Access to access_control-Protected GET Routes
High Also affects symfony/symfony
GHSA-x5qj-865h-mgvm
Symfony: HtmlSanitizer UrlAttributeSanitizer Misses URL Attributes
Medium Also affects symfony/symfony
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