Symfony: NoPrivateNetworkHttpClient Does Not Pin the Checked IP of Cached Hosts, Letting DNS Rebinding Enumerate Internal Ports (Incomplete Fix for CVE-2024-50342)

Summary

CVECVE-2026-123119
StatePUBLISHED
AssignerCheckmarx
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-11-05 13:17:07 UTC
Updated2026-11-05 13:17:07 UTC
DescriptionThe Symfony HttpClient component NoPrivateNetworkHttpClient does not pin the checked IP address of cached hosts, allowing for DNS rebinding to bypass private network restrictions, resulting in enumeration of internal hosts and ports 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. NoPrivateNetworkHttpClient resolves the host of each request and checks the IP before connecting. It caches the result per host, and passes the IP to the decorated client through the resolve option so that the client connects to the exact IP that was checked. The issue is that resolve was only passed on the first lookup of a host: on subsequent requests, the decorated client resolved the host again on its own. An attacker who controls a host's DNS can exploit this with DNS rebinding by answering the first lookup with a public IP, and subsequent lookups with a private IP, so when an application sends several requests to that host through the same client, the later requests connect to the private IP. This happens, for example, when an application fetches several URLs of a repository provided by a user. The check of the primary_ip in the on_progress callback still aborts the request before anything is sent, but the connection is made, and the error differs depending on whether the port is open or closed. This allows enumerating internal hosts and ports, as in CVE-2024-50342.

Risk And Classification

Primary CVSS: v4.0 2.3 LOW from 596c5446-0ce5-4ba2-aa66-48b3b757a647

CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:N/SC:L/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Problem Types: CWE-367 | CWE-918 | CWE-367 CWE-367 Time-of-check time-of-use (TOCTOU) race condition | CWE-918 CWE-918 Server-Side request forgery (SSRF)


VersionSourceTypeScoreSeverityVector
4.0596c5446-0ce5-4ba2-aa66-48b3b757a647Secondary2.3LOWCVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:N/SC:L/SI:N/SA:N/E:X/C...
4.0CNACVSS2.3LOWCVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:N/SC:L/SI:N/SA:N

CVSS v4.0 Breakdown

Attack Vector
Network
Attack Complexity
Low
Attack Requirements
Present
Privileges Required
Low
User Interaction
None
Confidentiality
None
Integrity
None
Availability
None
Sub Conf.
Low
Sub Integrity
None
Sub Availability
None

CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:N/SC:L/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Sensiolabs Symfony affected 5.4.56 git Not specified
CNA Sensiolabs Symfony affected 6.0.0 6.4.50 git Not specified
CNA Sensiolabs Symfony affected 7.0.0 7.4.23 git Not specified
CNA Sensiolabs Symfony affected 8.0.0 8.1.11 git Not specified

References

ReferenceSourceLinkTags
github.com/symfony/symfony/security/advisories/GHSA-c7hm-wqwp-f9v8 596c5446-0ce5-4ba2-aa66-48b3b757a647 github.com
github.com/symfony/symfony/commit/ab084826b2b5db8d0b91af635fe2b5e1c4f699f9 596c5446-0ce5-4ba2-aa66-48b3b757a647 github.com
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Vendor Comments And Credit

Discovery Credit

CNA: Eirik Stanghelle Morland from Packagist (en)

CNA: Nicolas Grekas (en)

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