What is CVE-2026-103956?
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.
The record classifies CVE-2026-103956 under weakness classes CWE-306, CWE-1188. Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs no prior authentication, needs no user interaction, and has high impact on confidentiality, integrity, availability. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 22 days ago.
Severity and exploitation probability
- CVSS v3.1 base score
- 10 — CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H - CVSS v4.0 base score
- 10
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H - EPSS (FIRST)
- 0.4% probability of exploitation in the next 30 days, higher than 38.5% of all scored CVEs
- CISA KEV
- Not listed in the CISA Known Exploited Vulnerabilities catalog
- Threadlinqs priority
- 8.5/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- Published
- 2026-10-02, last modified 2026-10-09
Is CVE-2026-103956 being exploited?
Weaponised exploit code for CVE-2026-103956 is publicly available. 1 public proof-of-concept repository is tracked for this identifier. It currently carries a trending score of 51 in the Threadlinqs vulnerability feed.
- abraxas/cve-2026-103956-loom-unauth (github)
Affected products and versions
- AWS: loom
How to fix CVE-2026-103956
No vendor patch reference has been recorded for CVE-2026-103956 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.
Threat activity tracking CVE-2026-103956
1 tracked threat in the Threadlinqs corpus references CVE-2026-103956, either in the campaign’s CVE list or as an indicator on the campaign record.
Sources
Enriched from CVE.org, FIRST EPSS, public proof-of-concept repositories. Last verified by Threadlinqs on .