CVE-2026-87913 Missing S3 bucket ownership verification in the AWS Security Agent MCP server
Attackers can steal private source archives and credentials by exploiting missing S3 bucket ownership checks in the AWS Security Agent MCP server.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-87913?
CVE-2026-87913 is a medium-severity missing authorization vulnerability in AWS Security Agent MCP server, published on 10 Sep 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
A missing S3 bucket ownership verification in the AWS Security Agent MCP server before 0.2.0 version might allow remote attackers to obtain the private source archive of a scanned workspace, including credentials and infrastructure state contained in that archive, via a pre-registered storage bucket whose name is derived from a publicly known account identifier.
To remediate this issue, users should upgrade to version 0.2.0. Users should also verify that the scan output bucket in their account is owned by their own account, because upgrading does not release a bucket name that a third party has already registered.
Which versions are affected by CVE-2026-87913?
How do I fix CVE-2026-87913?
No fix has been published for CVE-2026-87913 yet. Limit exposure of the affected software until one is available.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-87913 being exploited?
There is no known exploitation of CVE-2026-87913 in the wild and no public exploit code.