The Symfony Validator component IpValidator incompletely classifies internal addresses in the filtered modes of the Ip constraint, so some…
CVE-2026-123125
The Symfony Validator component IpValidator incompletely classifies internal addresses in the filtered modes of the Ip constraint, so some internal addresses are accepted as public, which can lead to Server-Side Request Forgery (SSRF) 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. In these modes, IpValidator relies on the PHP flags FILTERFLAGNOPRIVRANGE and FILTERFLAGNORESRANGE to classify addresses as public, private, or reserved. These flags do not cover shared address space (100.64.0.0/10) or IPv4-mapped, IPv4-compatible, and 6to4 IPv6 addresses, which can embed internal IPv4 addresses. A value such as ::ffff:127.0.0.1 can therefore pass validation even though it points to an internal host. Applications that rely on the Ip constraint to reject internal addresses, for example before making a server-side request to a user-supplied address, can be exposed to SSRF.
Assessment
- CVSS
- 6.3 (v4.0)
- Severity
- Medium
- Known exploited
- Not listed in CISA KEV
- Exploit availability
- Nothing found in Exploit-DB, Metasploit, Nuclei or public PoC repositories
- Published
- 5 November 2026
- Last updated
- 5 November 2026
- Affected
- sensiolabs · symfony
- Assigner
- Checkmarx
CVSS vectorCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N
At the source
References
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