CVE-2026-89090

MEDIUMPre-NVD 5.95.9
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 5.9 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.3%, top 76% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
5.9EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 5.9Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

An unrecovered panic in the event stream header decoder in Amazon AWS SDK for Go v2 before release-2026-03-23 might allow an unauthenticated remote actor to terminate the consuming application process via a crafted event stream response frame containing a header value type outside the valid range.

To remediate this issue, users should upgrade to release-2026-03-23 or later, and patch any forked or derivative code.

CVSS v3
5.9
EG Score
5.9(medium)
EG Risk
27(Track)
EG Risk 27/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity59% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
24%
KEV
Not listed

Published

September 11, 2026

Last Modified

September 11, 2026

Advisory Details (3)

Auto-updated Sep 11, 2026
Patch available. Sources: github, github_release.
generic

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

https://aws.amazon.com/security/security-bulletins/2026-110-aws/
github_release Patch Available

Release (2026-03-23)

Patch available: aws/aws-sdk-go-v2 release-2026-03-23

https://github.com/aws/aws-sdk-go-v2/releases/tag/release-2026-03-23
github Patch Available

Denial of Service due to Panic in AWS SDK for Go v2 SDK EventStream Decoder · Advisory · aws/aws-sdk-go-v2 · GitHub

https://github.com/aws/aws-sdk-go-v2/security/advisories/GHSA-xmrv-pmrh-hhx2

Vendor Advisories for CVE-2026-89090(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Affected Packages

(12 across 1 ecosystem)

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 12× in last 7d / 17× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-09-18 19:28 UTCEPSS rescore
  2. 2026-09-18 04:54 UTCEG score recompute
  3. 2026-09-17 19:32 UTCEPSS rescore
  4. 2026-09-17 03:33 UTCEG score recompute
  5. 2026-09-16 14:09 UTCEPSS rescore
  6. 2026-09-16 05:15 UTCEPSS rescore
  7. 2026-09-16 02:12 UTCEG score recompute
  8. 2026-09-15 03:12 UTCEPSS rescore
  9. 2026-09-13 23:29 UTCEG score recompute
  10. 2026-09-13 16:48 UTCEPSS rescore
  11. 2026-09-12 22:08 UTCEG score recompute
  12. 2026-09-12 15:02 UTCEPSS rescore
  13. 2026-09-11 20:46 UTCEG score recompute
  14. 2026-09-11 19:28 UTCEG score recompute
  15. 2026-09-11 18:34 UTCEG score recompute
  16. 2026-09-11 17:19 UTCEG score recompute
  17. 2026-09-11 17:18 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-89090?
CVE-2026-89090 is a medium vulnerability published on September 11, 2026. An unrecovered panic in the event stream header decoder in Amazon AWS SDK for Go v2 before release-2026-03-23 might allow an unauthenticated remote actor to terminate the consuming application process via a crafted event stream response frame containing a header value type outside the valid range.…
When was CVE-2026-89090 disclosed?
CVE-2026-89090 was first published in the National Vulnerability Database on September 11, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-89090 actively exploited?
CVE-2026-89090 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 76.1% of all scored CVEs.
What is the CVSS score of CVE-2026-89090?
CVE-2026-89090 has a CVSS v3 base score of 5.9 (NVD).
How do I remediate CVE-2026-89090?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-89090, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-89090

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Is Your Infrastructure Affected by CVE-2026-89090?

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