CVE-2026-93491

HIGHPre-NVD 7.57.5—
EchelonGraph scoreHIGH confidence

Score 7.5 from GitHub Security Advisory (severity: HIGH) published 2026-09-18. a secondary CVSS source baseline 7.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 4 sources updated this week
7.5EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.5Exploit: None knownExposed: 0

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

A flaw was found in Netty's HttpServerCodec. A remote, unauthenticated attacker can exploit this vulnerability by pipelining HTTP/1.1 requests on a single connection and withholding reads. This action causes the methodOverflowQueue to grow without limit, leading to unbounded heap memory consumption and a denial of service due to memory exhaustion.

CVSS v3
7.5
EG Score
7.5(high)
EG Risk
49(Track)
EG Risk 49/100SSVC: 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
Severity75% × 45%
Exploitation0% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
38%
KEV
Not listed

Published

September 18, 2026

Last Modified

September 18, 2026

Advisory Details (4)

Auto-updated Sep 18, 2026
Patch available. Sources: github_release, redhat.
github_release Patch Available

netty-4.2.18.Final

Patch available: netty/netty netty-4.2.18.Final

https://github.com/netty/netty/releases/tag/netty-4.2.18.Final
github_release Patch Available

netty-4.1.138.Final

Patch available: netty/netty netty-4.1.138.Final

https://github.com/netty/netty/releases/tag/netty-4.1.138.Final
redhat

2536891 – (CVE-2026-93491) CVE-2026-93491 io.netty/netty-codec-http: Netty: Denial of Service via unbounded HttpServerCodec HTTP/1.1 pipeline queue

https://bugzilla.redhat.com/show_bug.cgi?id=2536891
redhat Patch Available

CVE-2026-93491 - Red Hat Customer Portal

Affected: Red Hat Enterprise Linux 8 or OpenShift Container Platform 4, is affected by this vulnerability and a fix may be released to a

https://access.redhat.com/security/cve/CVE-2026-93491

Vendor Advisories for CVE-2026-93491(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 16× in last 7d / 16× 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 23:50 UTCEG score recompute
  2. 2026-09-20 23:50 UTCGHSA enrichment
  3. 2026-09-20 20:16 UTCEPSS rescore
  4. 2026-09-20 11:15 UTCGHSA enrichment
  5. 2026-09-19 22:39 UTCEG score recompute
  6. 2026-09-19 22:39 UTCGHSA enrichment
  7. 2026-09-19 10:03 UTCGHSA enrichment
  8. 2026-09-18 21:28 UTCEG score recompute
  9. 2026-09-18 21:28 UTCGHSA enrichment
  10. 2026-09-18 20:29 UTCEG score recompute
  11. 2026-09-18 20:29 UTCGHSA enrichment
  12. 2026-09-18 19:08 UTCEG score recompute
  13. 2026-09-18 19:08 UTCGHSA enrichment
  14. 2026-09-18 13:22 UTCEG score recompute
  15. 2026-09-18 12:54 UTCEG score recompute
  16. 2026-09-18 12:54 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-93491?
CVE-2026-93491 is a high vulnerability published on September 18, 2026. A flaw was found in Netty's HttpServerCodec. A remote, unauthenticated attacker can exploit this vulnerability by pipelining HTTP/1.1 requests on a single connection and withholding reads. This action causes the methodOverflowQueue to grow without limit, leading to unbounded heap memory consumption…
When was CVE-2026-93491 disclosed?
CVE-2026-93491 was first published in the National Vulnerability Database 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-2026-93491 actively exploited?
CVE-2026-93491 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 62.3% of all scored CVEs.
What is the CVSS score of CVE-2026-93491?
CVE-2026-93491 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2026-93491?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-93491, 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-2026-93491

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