One CVE, Root Privileges: SSM Agent's Path Traversal Bug

A genuinely quiet week closes with a single but serious finding: a path traversal flaw in the SSM Agent's download-content plugin can be abused to write files - with root privileges - outside the intended directory.

In this issue1high

CVEs & Vulnerabilities

1 item

$ cat /var/reports/CVE_REPORT.txt

high/CVE/August 28, 2026

CVE-2026-81849: Path Traversal in SSM Agent's Download-Content Plugin

CVE-2026-81849 Bulletin 2026-091-AWS

The aws:downloadContent plugin in amazon-ssm-agent improperly limits pathnames to a restricted directory. An authenticated remote user holding ssm:SendCommand permission scoped to the AWS-DownloadContent document can direct the agent to fetch a crafted S3 object whose key traverses outside the intended download directory, writing arbitrary files with root privileges - potentially leading to code execution if sensitive system files are overwritten. Affects SSM Agent 2.0.767.0 through 3.3.4364.0; fixed in 3.3.4515.0.

Affected

amazon-ssm-agent 2.0.767.0-3.3.4364.0

Fixed In

amazon-ssm-agent 3.3.4515.0

Systems Manager

Key Takeaway

1 item

$ cat WEEKLY_SUMMARY.md

The blast radius here depends entirely on how tightly you scope ssm:SendCommand - if any principal beyond a small break-glass set can invoke AWS-DownloadContent, treat this as urgent. Everyone else should still patch to 3.3.4515.0 on the normal cycle; this is a light week otherwise.

Filed Under

Systems ManagerCVEPath Traversal

Week 34 - Aug 17-23, 2026

Week 36 - Aug 31 - Sep 6, 2026

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