CVE-2026-103957 AWS CVE debrief

Who should care

AWS users with Loom for AWS deployments should assess exposure and prioritize patching to version 1.7.0 or later. Users with Loom for AWS deployments prior to version 1.7.0 are affected and should take immediate action to patch the vulnerability. Security teams and vulnerability management teams should review the vulnerability and assess the impact on their organization.

Why it matters

CVE-2026-103957 is a medium-severity vulnerability in Loom for AWS that requires patching to prevent potential unauthorized access and requests to internal network locations.

• Potential unauthorized access to user access tokens
• Possible requests to arbitrary internal network locations
• Need for verification of current Loom for AWS version and configurations
• Potential impact on internal network security

Technical summary

The vulnerability exists in Loom for AWS before version 1.7.0, allowing an authenticated remote user to potentially obtain the access token of another user and cause the application to issue requests to arbitrary internal network locations via a crafted discovery document address. This vulnerability requires patching to prevent potential unauthorized access and requests to internal network locations. The vulnerability affects Loom for AWS deployments prior to version 1.7.0. Users with Loom for AWS deployments should assess exposure and prioritize patching to version 1.7.0 or later.

Defensive priority

Medium-priority patching required for Loom for AWS instances

Recommended defensive actions

• Upgrade Loom for AWS to version 1.7.0 or later
• Review and restrict OAuth2 discovery handling configurations
• Monitor for suspicious requests to internal network locations
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The CVE record and source item provide details on the vulnerability, affected versions, and remediation steps. The vulnerability was reported by an external researcher and verified by the vendor. The vendor has released a patch for the vulnerability, which is available in version 1.7.0 or later of Loom for AWS. The vulnerability affects Loom for AWS deployments prior to version 1.7.0. Defenders should verify current Loom for AWS versions and configurations, and review OAuth2 discovery handling configurations.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.