CVE-2026-100658

✕ Withdrawn — historical dataMEDIUMPre-NVD 5.3Trending — 3 sources updated this week
5.3CVSS
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.3%CVSS: 5.3Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

Netty (io.netty:netty-codec-http) contains an unbounded per-connection queue in WebSocketServerExtensionHandler. The handler offers an entry to its per-channel validExtensions queue for every inbound HttpRequest, but polls an entry only when the application writes an HttpResponse, and the queue size is never bounded. A remote, unauthenticated peer can use HTTP/1.1 pipelining to send requests faster than the application produces responses — including plain non-upgrade HTTP requests to any path — causing the queue to grow without limit until the JVM exhausts heap memory and terminates with OutOfMemoryError. Because the affected handler is the base class of WebSocketServerCompressionHandler, any server that enables permessage-deflate is exposed on its plain HTTP port before any WebSocket upgrade completes and before any application-level authentication. Affected versions are 4.1.88.Final through 4.1.137.Final and 4.2.0.Final through 4.2.17.Final; the issue is fixed in 4.1.138.Final and 4.2.18.Final.

CVSS v3
5.3
EchelonGraph score
Not yet assessedThis CVE record was withdrawn by its numbering authority, so there is no vulnerability to rate.
EG Score
—
EG Risk
—
EPSS PROB
0.3%
EPSS %ILE
25th
KEV
Not listed

Published

September 26, 2026

Last Modified

September 28, 2026

Advisory Details (2)

Auto-updated Sep 26, 2026
🔬 Proof of concept available. Patch available. Sources: github.
generic

Netty before 4.1.138.Final Denial of Service via WebSocketServerExtensionHandler | Advisories | VulnCheck

https://www.vulncheck.com/advisories/netty-before-4.1.138-final-denial-of-service-via-websocketserverextensionhandler
github Patch Available🟡 PoC Available

Unbounded Per-Connection Queue Growth in WebSocketServerExtensionHandler Leads to Denial of Service · Advisory · netty/netty · GitHub

https://github.com/netty/netty/security/advisories/GHSA-2g37-3h88-55hc

Vendor Advisories for CVE-2026-100658(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 6× in last 7d / 15× 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. 2026-10-02 17:20 UTCGHSA enrichment
  2. 2026-09-29 17:03 UTCEG score recompute▼ 5.30
  3. 2026-09-29 17:03 UTCGHSA enrichment
  4. 2026-09-28 15:27 UTCEG score recompute
  5. 2026-09-28 15:27 UTCGHSA enrichment
  6. 2026-09-28 13:50 UTCEPSS rescore
  7. 2026-09-27 17:24 UTCEG score recompute
  8. 2026-09-27 17:24 UTCGHSA enrichment
  9. 2026-09-27 16:36 UTCEG score recompute
  10. 2026-09-27 16:36 UTCGHSA enrichment
  11. 2026-09-27 16:10 UTCEG score recompute
  12. 2026-09-27 16:10 UTCGHSA enrichment
  13. 2026-09-26 14:33 UTCEG score recompute
  14. 2026-09-26 13:38 UTCEG score recompute
  15. 2026-09-26 13:30 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-100658?
CVE-2026-100658 is a medium vulnerability published on September 26, 2026. Netty (io.netty:netty-codec-http) contains an unbounded per-connection queue in WebSocketServerExtensionHandler. The handler offers an entry to its per-channel validExtensions queue for every inbound HttpRequest, but polls an entry only when the application writes an HttpResponse, and the queue…
When was CVE-2026-100658 disclosed?
CVE-2026-100658 was first published on September 26, 2026, with the most recent update on September 28, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-100658 actively exploited?
CVE-2026-100658 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.3% probability of exploitation in the next 30 days (25th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-100658?
CVE-2026-100658 has a CVSS base score of 5.3 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-100658?
A fix for CVE-2026-100658 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-100658 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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