CVE-2026-122193 OS command injection in the example SSM documents in Trusted Remote Execution (REX)

CriticalCVSS 9.3

Published: 2026-11-06 19:09
Updated: 2026-11-06 22:35
Exploit status: No public exploit known

Description

OS command injection in the example SSM document provisioning script in Trusted Remote Execution (REX) before 2026-07-28 might allow an authenticated remote user who is permitted to invoke the Rex-RO or Rex-RW SSM document to execute arbitrary commands as root on the managed instance, bypassing Cedar policy enforcement.

To remediate this issue, users should delete any Rex-RO and Rex-RW SSM documents created from the example script, in each account and Region where it was run.

Affected products

Product	Affected versions	Fixed in
AWS trusted-remote-execution	All versions	No fix listed

References

aws.amazon.com vendor-advisory
github.com third-party-advisory

CVSS v4.0

9.3 Critical

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:L/SA:N

Attack Vector: Network
Attack Complexity: Low
Attack Requirements: None
Privileges Required: Low
User Interaction: None
Vulnerable System Confidentiality: High
Vulnerable System Integrity: High
Vulnerable System Availability: High
Subsequent System Confidentiality: High
Subsequent System Integrity: Low
Subsequent System Availability: None

All scores (2)

v4.0 9.3 · amzn
v3.1 9.9 · amzn

Weakness & likelihood

EPSS (exploitation probability, 30 days): Not available
CWE: CWE-78 Improper neutralization of special elements used in an OS command ('OS command injection')

Public exploit references

Metadata only. CVERadar never hosts or runs exploit code.

No public exploit references known.