CVE-2026-87913
CVE-2026-87913 is a medium-severity vulnerability with a CVSS 3.x base score of 5.9. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-283.
Key facts
- Severity: Medium (CVSS 3.x base score 5.9)
- CVSS v4: 5.1
- EPSS exploit prediction: 0% (36th percentile)
- Actively exploited: Not listed in CISA KEV
- Weakness: CWE-283
- Published:
- Last modified:
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.
Frequently asked questions
- What is CVE-2026-87913?
- 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.
- How severe is CVE-2026-87913?
- CVE-2026-87913 has a CVSS 3.x base score of 5.9, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity low, and availability none.
- Is CVE-2026-87913 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (36th percentile), an estimate of the probability of exploitation in the next 30 days.
- How do I fix CVE-2026-87913?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
- When was CVE-2026-87913 published?
- CVE-2026-87913 was published on 2026-09-10.
References
- https://aws.amazon.com/security/security-bulletins/2026-105-aws/
- https://github.com/awslabs/mcp/security/advisories/GHSA-3jxw-vj8m-8x77
- https://pypi.org/project/awslabs.security-agent-mcp-server/0.2.0/?refid=d8ec3b19-0f37-4f8c-8c12-189f913e205c
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