What is CVE-2026-18830?

CVE-2026-18830 is a high-severity vulnerability in AWS Amazon Bedrock Agentcore Harness, classified under CWE-1287. CVSS score: 8.1/10. Published 2026-08-04.

How severe is CVE-2026-18830?

High severity. CVSS v3 base score is 8.1 out of 10.

Is CVE-2026-18830 known to be exploited?

1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Vulnerability in AWS Amazon Bedrock Agentcore Harness

CVE-2026-18830

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.

EPSS: 0.005 (43.7th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N.

Affected products

Aws Amazon Bedrock Agentcore Harness — versions N/A

Weakness classification (CWE)

CWE-1287

Public proof-of-concept exploits

huzjie/aegisagent

References

ff89ba41-3aa1-4d27-914a-91399e9639e5 (vendor-advisory)

Frequently asked questions

What is CVE-2026-18830?: CVE-2026-18830 is a high-severity vulnerability in AWS Amazon Bedrock Agentcore Harness, classified under CWE-1287. CVSS score: 8.1/10. Published 2026-08-04.
How severe is CVE-2026-18830?: High severity. CVSS v3 base score is 8.1 out of 10.
Is CVE-2026-18830 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.