# CVE-2026-81849: Path traversal in the aws:downloadContent plugin in amazon-ssm-agent

> Authenticated users with restricted permissions can write arbitrary files as root via path traversal, potentially leading to code execution.

- **Severity:** High 8.7 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 28 Aug 2026
- **Updated:** 31 Aug 2026

## What is CVE-2026-81849?

CVE-2026-81849 is a high-severity path traversal vulnerability in amazon-ssm-agent, published on 28 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Improper limitation of a pathname to a restricted directory in the aws:downloadContent plugin in amazon-ssm-agent before 3.3.4515.0 might allow an authenticated remote user whose ssm:SendCommand permission is restricted to the AWS-DownloadContent document, to write arbitrary files outside the intended download directory with root privileges, via crafted object keys in the S3 source the document is directed to retrieve. This issue may lead to arbitrary code execution as root if specific sensitive files are overwritten.

To remediate this issue, customers should upgrade amazon-ssm-agent to version 3.3.4515.0 or later.

Weakness: CWE-23 (Relative Path Traversal)

## Which versions are affected by CVE-2026-81849?


## How do I fix CVE-2026-81849?

No fix has been published for CVE-2026-81849 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-81849 being exploited?

There is no known exploitation of CVE-2026-81849 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-81849 and fix it if it is affected.

What it is: CVE-2026-81849 is a high-severity path traversal vulnerability in amazon-ssm-agent, published on 28 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-81849 in the wild and no public exploit code.

Affected product: amazon-ssm-agent. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-81849/ (Markdown: https://insights.sbomify.com/CVE-2026-81849/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-81849
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-81849
- OSV: https://osv.dev/vulnerability/CVE-2026-81849

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-81849/
Summaries are generated and may contain mistakes; the official description above is the record.