Findings

CVE-2026-89090

CVE-2026-89090 - Denial of service in the event stream header decoder in AWS SDK for Go v2

Published Sep 11, 2026 · Amazon Web Services · evidence confidence high

Bulletin ID: 2026-110-AWS Scope: AWS Content Type: Important (requires attention) Publication Date: 09/11/2026 10:00 AM PDT Description: An issue exists in the the EventStream header decoder in AWS SDK for Go v2 in versions predating 2026-03-23. An actor can send a malformed EventStream response frame containing a crafted header value type byte outside the valid range, which can cause the host process to terminate. Impacted versions: Please refer to the article below for the most up-to-date

Grounded briefings

Catalog interpretations for three audiences. Each brief cites ingested metadata and the original advisories below. They are not independent research and they do not invent exploit steps.

Executive

CVE-2026-89090 is a unknown public vulnerability record for Amazon Web Services. It is not currently listed in the CISA Known Exploited catalog. Check the linked vendor or CERT advisories for patch status. This summary is a catalog interpretation of the ingested metadata and cites the original advisories below.

System administrator

Identify whether Amazon Web Services is in your estate, then compare installed versions with the affected ranges. Affected version ranges have not been ingested yet. Check the linked vendor or CERT advisories for patch status. Prefer the vendor or distribution advisory linked in Sources before changing production systems. This is a catalog interpretation, not a runbook.

Security analyst

Signals on file: no CVSS/EPSS yet. It is not currently listed in the CISA Known Exploited catalog. Sources contributing to this record: aws, cve_org. Public exploit references, when present, are outbound links only and are not proof of active exploitation. This is a catalog interpretation of stored metadata.

Exploitation and remediation

  • Exploitation evidence

    Not listed as known exploited in CISA KEV. Not in the CISA KEV catalog.

  • Patch and remediation

    No required-action text is stored yet. Use the vendor or CERT links in Sources for patch availability.

  • Safe detection guidance

    Compare installed versions with the affected ranges below and verify the advisory from the original publisher. This site stores metadata and outbound links only; it does not ship exploit code or proof-of-concept payloads.

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. Sep 11, 2026 · AWS Security Bulletins

    Detected

    Bulletin ID: 2026-110-AWS Scope: AWS Content Type: Important (requires attention) Publication Date: 09/11/2026 10:00 AM PDT Description: An issue exists in the the EventStream header decoder in AWS SDK for Go v2 in versions predating 2026-03-23. An actor can send a malformed EventStream response frame containing a crafted header value type byte outside the valid range, which can cause the host pro

Sources

  • AWS Security BulletinsVendor advisoryCVE-2026-89090

    Bulletin ID: 2026-110-AWS Scope: AWS Content Type: Important (requires attention) Publication Date: 09/11/2026 10:00 AM PDT Description: An issue exists in the the EventStream header decoder in AWS SDK for Go v2 in versions predating 2026-03-23. An actor can send a malformed Even

    aws.amazon.com
  • CVE.orgVulnerability recordCVE-2026-89090

    Official CVE identifier

    cve.org