CVE-2026-90439

MEDIUMPre-NVD 6.56.5—
EchelonGraph scoreHIGH confidence

Score 6.5 from GitHub Security Advisory published 2026-09-15. a secondary CVSS source baseline 6.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 4 sources updated this week
6.5EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 6.5Exploit: None knownExposed: 0

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

NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_v3_module module. When using HTTP/3 with OpenSSL versions <= OpenSSL 3.5.0 under certain configurations, a limited heap buffer overflow could happen while processing a TLS handshake. This can happen in a non-deterministic manner that is beyond the attacker's control. This may cause a heap buffer overflow in the NGINX worker process leading to a restart and/or limited data corruption.

Impact: This vulnerability may allow remote attackers to cause a denial-of-service (DoS) on the NGINX system or limited data corruption. There is no control plane exposure; this is a data plane issue only.

Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

CVSS v3
6.5
EG Score
6.5(high)
EG Risk
44(Track)
EG Risk 44/100SSVC: 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
Severity65% × 45%
Exploitation0% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
18%
KEV
Not listed

Published

September 15, 2026

Last Modified

September 18, 2026

Advisory Details (1)

Auto-updated Sep 15, 2026
No patch confirmed yet.
generic

myF5

https://my.f5.com/manage/s/article/K000162604

Vendor Advisories for CVE-2026-90439(1)

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

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 19× in last 7d / 19× 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. 2026-09-20 20:16 UTCEPSS rescore
  2. 2026-09-20 19:09 UTCGHSA enrichment
  3. 2026-09-19 19:29 UTCEG score recompute
  4. 2026-09-19 19:29 UTCGHSA enrichment
  5. 2026-09-18 19:48 UTCEG score recompute
  6. 2026-09-18 19:48 UTCGHSA enrichment
  7. 2026-09-18 19:28 UTCEPSS rescore
  8. 2026-09-18 19:03 UTCEG score recompute
  9. 2026-09-18 19:03 UTCGHSA enrichment
  10. 2026-09-17 19:32 UTCEPSS rescore
  11. 2026-09-17 19:22 UTCGHSA enrichment
  12. 2026-09-16 16:55 UTCGHSA enrichment
  13. 2026-09-16 15:12 UTCEG score recompute
  14. 2026-09-16 15:12 UTCGHSA enrichment
  15. 2026-09-16 14:09 UTCEPSS rescore
  16. 2026-09-15 15:31 UTCEG score recompute
  17. 2026-09-15 14:53 UTCEG score recompute
  18. 2026-09-15 14:33 UTCEG score recompute
  19. 2026-09-15 14:32 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-90439?
CVE-2026-90439 is a medium vulnerability published on September 15, 2026. NGINX Plus and NGINX Open Source have a vulnerability in the ngxhttpv3_module module. When using HTTP/3 with OpenSSL versions <= OpenSSL 3.5.0 under certain configurations, a limited heap buffer overflow could happen while processing a TLS handshake. This can happen in a non-deterministic manner…
When was CVE-2026-90439 disclosed?
CVE-2026-90439 was first published in the National Vulnerability Database on September 15, 2026, with the most recent update on September 18, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-90439 actively exploited?
CVE-2026-90439 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 82.4% of all scored CVEs.
What is the CVSS score of CVE-2026-90439?
CVE-2026-90439 has a CVSS v3 base score of 6.5 (NVD).
How do I remediate CVE-2026-90439?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-90439, 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

Explore the affected products and dependency analysis for CVE-2026-90439

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