CVE-2026-18830 Insufficient input validation in Amazon Bedrock AgentCore harness InvokeHarness API
Authenticated users can bypass security controls and execute tools via crafted messages in Amazon Bedrock AgentCore harness.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-18830?
CVE-2026-18830 is a high-severity vulnerability in AWS Amazon Bedrock AgentCore harness, published on 4 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Insufficient input validation in Amazon Bedrock AgentCore harness might allow an authenticated remote user to execute configured tools bypassing model invocation and security controls via crafted content blocks in conversation messages. AWS has addressed this issue. No customer action is required.
Weakness: CWE-1287
Which versions are affected by CVE-2026-18830?
How do I fix CVE-2026-18830?
No fix has been published for CVE-2026-18830 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-18830 being exploited?
There is no known exploitation of CVE-2026-18830 in the wild and no public exploit code.
Public exploit code: 1 proofs of concept on GitHub.
Sources
Also known as GHSA-h8gv-mm2p-4q56.