In these modes, IpValidator relies on the PHP flags FILTER_FLAG_NO_PRIV_RANGE and FILTER_FLAG_NO_RES_RANGE 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.
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | |||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| sensiolabs | symfony | unaffected |
|
No data.
No data.
No data.
No advisories yet.
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
Thu, 05 Nov 2026 17:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
cvssV3_1
|
Thu, 05 Nov 2026 16:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | 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 FILTER_FLAG_NO_PRIV_RANGE and FILTER_FLAG_NO_RES_RANGE 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. | |
| Title | Symfony: Ip Constraint public/private Modes Accept IPv4-Mapped and IPv4-Compatible IPv6 Addresses allowing SSRF Filter Bypass | |
| First Time appeared |
Sensiolabs
Sensiolabs symfony |
|
| Weaknesses | CWE-184 CWE-918 |
|
| CPEs | cpe:2.3:a:sensiolabs:symfony:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Sensiolabs
Sensiolabs symfony |
|
| References |
| |
| Metrics |
cvssV4_0
|
Projects
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MITRE
Status: PUBLISHED
Assigner: Checkmarx
Published:
Updated: 2026-11-05T17:00:21.546Z
Reserved: 2026-11-05T13:05:37.986Z
Link: CVE-2026-123125
Vulnrichment
No data.
NVD
Status : Received
Published: 2026-11-05T16:17:46.940
Modified: 2026-11-05T17:18:03.140
Link: CVE-2026-123125
Redhat
No data.
OpenCVE Enrichment
No data.