CVE-2026-121581 in ArcReel
Summary
by MITRE • 11/04/2026
A vulnerability has been found in ArcReel 0.32.0/0.33.0/0.34.0. The impacted element is an unknown function of the file /api/v1/providers/{id}/test of the component Provider Test-Connection Endpoint. The manipulation leads to server-side request forgery. Remote exploitation of the attack is possible. The exploit has been disclosed to the public and may be used. The vendor was contacted early about this disclosure but did not respond in any way.
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Analysis
by VulDB Data Team • 11/04/2026
The vulnerability identified within ArcReel versions 0.32.0 through 0.34.0 represents a critical server-side request forgery flaw located specifically within the Provider Test-Connection Endpoint, accessible via the API path /api/v1/providers/{id}/test. This component is designed to validate connectivity with external providers, yet it fails to adequately sanitize or restrict the destination addresses used during these connection tests. The core technical deficiency lies in an unknown function that processes user-supplied input without implementing sufficient validation controls against internal network resources. By manipulating this endpoint, a remote attacker can instruct the server to initiate HTTP requests to arbitrary destinations, effectively leveraging the application's elevated privileges and network access to probe or interact with backend infrastructure that would otherwise be inaccessible from the public internet.
This type of vulnerability is classically categorized under CWE-918, which defines Server-Side Request Forgery as a flaw where an attacker causes the server-side application to make requests to unintended locations. The operational impact of this weakness extends beyond simple data exfiltration; it enables attackers to perform network reconnaissance against internal services such as databases, administrative panels, or other microservices residing on the same private network segment. Since the vulnerability allows for remote exploitation without authentication requirements in many configurations, it serves as a potent entry point for further compromise. Attackers can utilize this vector to bypass firewalls and access control lists that rely solely on perimeter defenses, thereby gaining insight into the internal architecture or potentially exploiting other vulnerabilities present on those internal targets.
The severity of this issue is compounded by the fact that proof-of-concept exploits have been publicly disclosed, lowering the barrier to entry for malicious actors who may lack sophisticated development skills but possess basic knowledge of web application attacks. Furthermore, the vendor's failure to respond to early disclosure attempts has left users without official patches or mitigation guidance during a critical window where exploitation risk is highest. This situation aligns with ATT&CK technique T1598, specifically Phishing for Inbound Information, as well as T1071 Application Layer Protocol when used in conjunction with other techniques like T1046 Network Service Discovery to map out the internal network topology from a compromised web application instance.
To mitigate this risk immediately, organizations running affected versions of ArcReel should implement strict input validation on all parameters passed to the test-connection endpoint, ensuring that only whitelisted domains or IP ranges are permitted for outbound requests. Additionally, deploying Web Application Firewalls with rulesets capable of detecting and blocking SSRF patterns can provide a layer of defense while patches are developed. It is also advisable to isolate the ArcReel application in a restricted network zone with limited egress permissions, preventing it from reaching sensitive internal resources even if an attacker successfully exploits this vulnerability. Until official updates are released by the vendor, continuous monitoring for anomalous outbound traffic originating from the server hosting ArcReel is recommended to detect potential exploitation attempts.