CVE-2026-121623 (GCVE-0-2026-121623)

Vulnerability from cvelistv5 – Published: 2026-11-06 16:08 – Updated: 2026-11-06 16:08
VLAI
Title
Symfony: DataUriNormalizer Opens Data URIs With a Non-Lowercase Scheme as Local Files, Letting a Client Read Any Server File
Summary
The Symfony Serializer component DataUriNormalizer::denormalize() matches the data: scheme with a case-sensitive regular expression, allowing a value with an uppercase scheme, such as DATA:,/../../../etc/passwd, to bypass it, resulting in Arbitrary Local File Read through Path Traversal in Symfony versions prior to 5.4.56, 6.x prior to 6.4.50, 7.x prior to 7.4.23, and 8.x prior to 8.1.11. A value whose scheme is not lowercase data: are treated as a local file path and opened instead of being decoded as inline data, so the resulting File, \SplFileInfo, or \SplFileObject points at a file on the server, which the application then handles as the uploaded content. Any endpoint that deserializes untrusted input into one of these types is affected. FrameworkBundle registers DataUriNormalizer ahead of ObjectNormalizer by default. A single request with a crafted DATA: value is enough to read arbitrary local files that the application can access, with no authentication needed if the endpoint is public.
Severity
8.2 (High)
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
CWE
  • CWE-73 - External control of file name or path
  • CWE-22 - Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
Assigner
Checkmarx CNA under the mitre root
CNA scorecard B 88/100 over 23 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
sensiolabs symfony Affected: 0 , < 5.4.56 (git)
Affected: 6.0.0 , < 6.4.50 (git)
Affected: 7.0.0 , < 7.4.23 (git)
Affected: 8.0.0 , < 8.1.11 (git)
guessed Create a notification for this product.
Credits
Nicolas Grekas
Show details on NVD website
To clipboard 

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