CVE-2026-47861 in Spring Integration
Summary
by MITRE • 08/27/2026
An unauthenticated remote attacker who can send a single UDP packet to a Spring Integration UDP inbound adapter can cause the server to emit an outbound UDP datagram to an arbitrary internal or external host and port of the attacker's choosing. Spring Integration 7.1.0 Spring Integration 7.0.0 - 7.0.5 Spring Integration 6.5.0 - 6.5.10 Spring Integration 6.4.0 - 6.4.12 Spring Integration 5.5.21 and earlier
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Analysis
by VulDB Data Team • 08/27/2026
The vulnerability described involves a critical flaw within the Spring Integration UDP inbound adapter, specifically affecting versions ranging from 5.5.21 and earlier through to version 7.1.0. This security issue stems from an insufficient validation of input parameters received via User Datagram Protocol packets. An unauthenticated remote attacker who possesses network connectivity to the affected service can exploit this flaw by sending a single, carefully crafted UDP packet. The core technical deficiency lies in the application's failure to restrict or validate the destination address and port specified within the payload for outbound responses. Consequently, instead of responding only to legitimate internal services or expected endpoints, the server is coerced into emitting an outbound UDP datagram directed at any arbitrary host and port selected by the attacker. This behavior effectively transforms the vulnerable Spring Integration instance into a network-based amplification vector or a pivot point for lateral movement within the target infrastructure.
From a technical perspective, this vulnerability aligns with CWE-20 Improper Input Validation, as the system fails to sanitize or verify the destination information contained in the incoming UDP message before processing it for outbound transmission. The operational impact is significant because it allows an attacker to perform unauthorized network reconnaissance by probing internal ports that are not exposed to the public internet but may be accessible from the server's network segment. Furthermore, this capability can facilitate more complex attacks such as DNS amplification if the target port corresponds to a DNS service, or it can be used to bypass firewall rules that rely on source IP verification for outbound traffic restrictions. The ability to send packets to arbitrary internal hosts makes this particularly dangerous in microservices architectures where inter-service communication relies heavily on UDP-based protocols like gRPC over HTTP/2 or custom binary protocols.
In the context of cybersecurity frameworks, this vulnerability maps directly to MITRE ATT&CK technique T1046 Network Service Discovery, as it enables an attacker to scan and identify active services within a private network segment from a compromised host. It also relates to T1571 Non-Standard Port Communication if the attacker utilizes non-standard ports for command and control channels that are less likely to be monitored by traditional security appliances. The lack of authentication required to trigger this behavior classifies it as an unauthenticated attack vector, which significantly lowers the barrier to entry for malicious actors compared to vulnerabilities requiring valid credentials or prior compromise.
Mitigation strategies must focus on immediate patching and architectural hardening. Organizations running affected versions of Spring Integration should upgrade to a version where this issue has been resolved, ensuring that input validation logic correctly restricts outbound destinations to a predefined whitelist of allowed hosts and ports. If upgrading is not immediately feasible, network-level controls such as strict egress filtering rules on firewalls can be implemented to block UDP traffic from the application server to unauthorized internal subnets or external IP ranges. Additionally, implementing ingress filters that drop malformed or unexpected UDP packets at the network perimeter can reduce the attack surface by preventing malicious payloads from reaching the vulnerable adapter in the first place. Continuous monitoring of outbound UDP traffic patterns should also be established to detect anomalous behavior indicative of exploitation attempts.