vulntracker.iovulntracker.io
© 2026 vulntracker.io

CVE-2026-4269

Improper S3 ownership verification in Bedrock AgentCore Starter Toolkit

HIGH
7.5
CVSS Score
Published: March 16, 2026 at 06:03 PM UTC
Updated: June 17, 2026 at 10:56 AM UTC
2 products affected across 2 vendorsBedrock Agentcore Starter ToolkitBedrock AgentCore Starter Toolkit

Using Bedrock AgentCore Starter Toolkit by AWS?

Get instant alerts when new vulnerabilities affect Bedrock AgentCore Starter Toolkit - before attackers find them.

Real-time alertsTrack your software stackFree plan available
Start FreeSign In
Severity
HIGH7.5
Exploit prediction
EPSS 0.3%
SSVC
No known exploit

Description

A missing S3 ownership verification in the Bedrock AgentCore Starter Toolkit before version v0.1.13 may allow a remote actor to inject code during the build process, leading to code execution in the AgentCore Runtime. This issue only affects users of the Bedrock AgentCore Starter Toolkit before version v0.1.13 who build or have built the Toolkit after September 24, 2025. Any users on a version >=v0.1.13, and any users on previous versions who built the toolkit before September 24, 2025 are not affected. To remediate this issue, customers should upgrade to version v0.1.13.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Bedrock Agentcore Starter Toolkit· Amazonpypi
95%
v < 0.1.13
Bedrock AgentCore Starter Toolkit· AWS
60%
0.1.0 ≤ v < 0.1.130.1.0
Affected range stops below 0.1.13, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

Patch and advisory references

References (2)

PatchRelease Notes
Source: cverecord
https://github.com/aws/bedrock-agentcore-starter-toolkit/releases/tag/v0.1.13
Vendor Advisory
Source: cverecord
https://aws.amazon.com/security/security-bulletins/2026-008-AWS/

SSVC — Action Prioritization

SSVCNo known exploitNot automatableTotal impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.5HIGHAMZN
Attack Vector
NETWORK
Complexity
HIGH
Privileges
NONE
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
CWE-340CWE-283

Get alerted

Stop reading CVE feeds looking for your own stack

Track the products you run and VulnTracker tells you when a new CVE affects them — with what is known about fixing it, and nothing about the rest.

Create accountSign in
Free plan, no card