Vulnerability Description
xmlseclibs is a library written in PHP for working with XML Encryption and Signatures. Versions 3.1.3 contain an authentication bypass vulnerability due to a flaw in the libxml2 canonicalization process during document transformation. When libxml2’s canonicalization is invoked on an invalid XML input, it may return an empty string rather than a canonicalized node. xmlseclibs then proceeds to compute the DigestValue over this empty string, treating it as if canonicalization succeeded. This issue is fixed in version 3.1.4. Workarounds include treating canonicalization failures (exceptions or nil/empty outputs) as fatal and aborting validation, and/or adding explicit checks to reject when canonicalize returns nil/empty or raises errors.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Xmlseclibs Project | Xmlseclibs | < 3.1.4 |
Related Weaknesses (CWE)
References
- https://github.com/robrichards/xmlseclibs/blob/f4131320c6dcd460f1b0c67f16f8bf24cProduct
- https://github.com/robrichards/xmlseclibs/commit/69fd63080bc47a8d51bc101c30b7cb7Patch
- https://github.com/robrichards/xmlseclibs/security/advisories/GHSA-c4cc-x928-vjwVendor AdvisoryExploit
FAQ
What is CVE-2025-66578?
CVE-2025-66578 is a vulnerability with a CVSS score of 6.0 (MEDIUM). xmlseclibs is a library written in PHP for working with XML Encryption and Signatures. Versions 3.1.3 contain an authentication bypass vulnerability due to a flaw in the libxml2 canonicalization proce...
How severe is CVE-2025-66578?
CVE-2025-66578 has been rated MEDIUM with a CVSS base score of 6.0/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2025-66578?
Check the references section above for vendor advisories and patch information. Affected products include: Xmlseclibs Project Xmlseclibs.