7.5

CVE-2026-4269: amazon bedrock_agentcore_starter_toolkit Unverified Ownership

CVSS: 7.5v3.1HighAnalyzed
AliasesGHSA-xfhr-q72q-jcrjPYSEC-2026-2396
Published 16-03-2026Last modified 16-03-2026
Open JSON

Vulnerability summary

CVE-2026-4269 is a high (CVSS 7.5) Unverified Ownership vulnerability in amazon bedrock_agentcore_starter_toolkit. EPSS estimates a 0.43% chance of exploitation in the next 30 days, higher than 36.3% of scored vulnerabilities.

Overall risk
30/100
0100
Medium · default modelHow is this calculated?
CVSS score
7.5/10
010
High · v3.1 (CVE.org)
EPSS score
0.43%
0%100%
Low · +0.19 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 16-03-2026
    PublishedVulnerability first disclosed.
  2. 16-03-2026
    Last modifiedVulnerability information updated.

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.

CVSS metrics

6 scores · 3 sources · 2 versions

EPSS trend

Probability

0.43%

Chance of exploitation in the next 30 days

Percentile

36%

Versus all other CVEs

30-day change

+0.19 pp

From 0.24% on 20-09-2026

20-09-202620-10-2026
EPSS score
0.43%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Amazon1 product
Aws1 product
PyPI1 product
  • bedrock-agentcore-starter-toolkit< 0.1.13

3 vendors · 3 products

References

8 links