CVE-2026-103956

Description

Missing authentication for critical function in the authentication dependency in Loom for AWS before 1.6.1 allowed remote actors to obtain super-admin authority over the agent control plane, including registering tool servers, reading stored integration credentials, and rewriting the IAM role policies attached to managed agent roles, via any request to the application API in a deployment where no identity provider is configured. To remediate this issue, users should upgrade to version 1.6.1 or later.

CVSS Metrics

• v4.0•CRITICAL•Score: 10CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H
• v4.0•CRITICAL•Score: 10CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/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
• v3.1•CRITICAL•Score: 10CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

Techniques & Countermeasures

• CWE-306•Missing Authentication for Critical Function

  The product does not perform any authentication for functionality that requires a provable user identity or consumes a significant amount of resources.

• CWE-1188•Initialization of a Resource with an Insecure Default

  The product initializes or sets a resource with a default that is intended to be changed by the product's installer, administrator, or maintainer, but the default is not secure.

Affected Systems

• aws•loom

  < 1.6.1

References (3)

• https://github.com/awslabs/loom/releases/tag/v1.6.1
• https://aws.amazon.com/security/security-bulletins/2026-124-aws/
• https://github.com/awslabs/loom/security/advisories/GHSA-vgmj-998f-r8mp