A serious authorization vulnerability has been discovered in Amazon Web Services’ Lambda setup, enabling attackers to sidestep IAM permissions and gain access to cloud services they shouldn’t be able to reach. Identified as CVE-2026-94384, the flaw exists in certain versions of the AmazonConnectSalesforceLambda application, used to connect Amazon Connect with Salesforce environments. Versions 5.15 through 5.24.16 are affected, AWS has confirmed.
At the heart of the issue is the sfExecuteAWSService Lambda function, which is active during the setup of the integration. The problem comes into play because this function doesn’t properly check who’s requesting the AWS operations it runs. That means a caller who has only the “lambda:InvokeFunction” privilege for this specific function may still trigger privileged AWS operations — operations that their own IAM policy would typically prevent. In other words, the function acts as a backdoor to privilege escalation.
Why This Matters
In AWS, IAM (Identity and Access Management) is designed to enforce least privilege: users or roles only have permissions they need. But with this flaw, a user with minimal permissions invoking sfExecuteAWSService could abuse the Lambda’s higher execution role to perform actions outside their allowed scope. This could include accessing services, modifying resources, or executing API calls that would normally be blocked.
The risk is most pronounced in environments where invocation permissions are widespread. Teams employing automation accounts, third-party integrations, or roles used by multiple people may inadvertently grant too much access. Once the initial setup is done, though, leaving this Lambda function active risks creating an attack surface that could be misused.
Mitigation Steps
AWS has already released patched version 5.26 of AmazonConnectSalesforceLambda to resolve CVE-2026-94384. Users on affected versions should upgrade immediately. Additionally, after completing the integration setup between Amazon Connect and Salesforce, it’s strongly advised to either delete or disable the sfExecuteAWSService Lambda function so it can no longer be invoked.
If keeping the function is unavoidable, organizations must tightly restrict who can invoke it. Only the single IAM user running the CTI Adapter should retain invoke rights. Other IAM users, roles, or groups should be denied access explicitly via Lambda resource policies, service control policies (SCPs), or permission boundaries. Furthermore, the SalesforceExecuteAWSServiceUser parameter should be configured to match the same IAM user to minimize risk of cross-account abuse.
Security teams are urged to audit IAM policies, Lambda resource permissions, execution roles, CloudTrail logs, and cross-account trust relationships to ensure this function isn’t misconfigured or left active. AWS credits Chang Li of Xidian University for reporting the issue through coordination disclosure.
What’s next: As organizations move more workloads into serverless and hybrid cloud setups, vulnerabilities like this that depend on misaligned IAM or overly permissive roles are becoming more critical. Proper cleanup after deployment—removing or locking down setup functions—is just as important as patching. For anyone running AmazonConnectSalesforceLambda, check your version, disable unused privileges, and verify that every invocation permission is strictly scoped.
