CVE-2026-100656

✕ Withdrawn — historical dataHIGHPre-NVD 7.5Trending — 3 sources updated this weekElevated
7.5CVSS
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.4%CVSS: 7.5Exploit: Elevated riskExposed services: Not assessed

A fix is available — apply it.

Netty (io.netty:netty-codec-http) contains an unbounded per-connection queue growth flaw in HttpServerCodec. The codec tracks the HTTP method of each still-unanswered pipelined request; the first 32 entries are bit-packed into a single long, but every additional entry is appended to methodOverflowQueue, an ArrayDeque with no size limit and no rejection path. A remote, unauthenticated attacker who pipelines HTTP/1.1 requests on a single connection while withholding reads on their own end (preventing responses from being flushed) can grow this queue without bound, causing unbounded heap growth and denial of service. Affected versions are 4.2.0.Final through 4.2.17.Final and all releases up to and including 4.1.137.Final; the issue is fixed in 4.2.18.Final and 4.1.138.Final.

CVSS v3
7.5
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Not yet assessedThis CVE record was withdrawn by its numbering authority, so there is no vulnerability to rate.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
0.4%
EPSS %ILE
34th
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 HttpServerCodec Unbounded Queue Growth via HTTP/1.1 Pipelining | Advisories | VulnCheck

https://www.vulncheck.com/advisories/netty-httpservercodec-unbounded-queue-growth-via-http-1.1-pipelining
github Patch Available🟡 PoC Available

Netty: [HttpServerCodec] Unbounded Per-Connection Queue Growth via HTTP/1.1 Pipelining · Advisory · netty/netty · GitHub

https://github.com/netty/netty/security/advisories/GHSA-pvjx-v7vp-62vq

Vendor Advisories for CVE-2026-100656(1)

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

Affected Packages

(3 across 3 ecosystems)
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
netty1:4.1.48-10 ... 1:4.1.48-9 (12 versions)
  • every version on: no fix on record
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
netty1:4.1.48-10 ... 1:4.1.48-16 (8 versions)
  • every version on: no fix on record
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
netty1:4.1.48-10 ... 1:4.1.48-16 (7 versions)
  • every version on: no fix on record
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 12× in last 7d / 23× 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. 2026-10-05 10:57 UTCGHSA enrichment
  2. 2026-10-02 07:48 UTCGHSA enrichment
  3. 2026-09-29 04:40 UTCEG score recompute▼ 7.50
  4. 2026-09-29 04:40 UTCGHSA enrichment
  5. 2026-09-28 17:42 UTCEG score recompute
  6. 2026-09-28 17:42 UTCGHSA enrichment
  7. 2026-09-28 17:00 UTCEG score recompute
  8. 2026-09-28 17:00 UTCGHSA enrichment
  9. 2026-09-28 15:27 UTCGHSA enrichment
  10. 2026-09-28 15:19 UTCEG score recompute
  11. 2026-09-28 15:19 UTCGHSA enrichment
  12. 2026-09-28 13:50 UTCEPSS rescore
  13. 2026-09-28 04:22 UTCGHSA enrichment
  14. 2026-09-27 17:24 UTCEG score recompute
  15. 2026-09-27 17:24 UTCGHSA enrichment
  16. 2026-09-27 16:36 UTCEG score recompute
  17. 2026-09-27 16:36 UTCGHSA enrichment
  18. 2026-09-27 12:28 UTCGHSA enrichment
  19. 2026-09-27 01:31 UTCEG score recompute
  20. 2026-09-27 01:31 UTCGHSA enrichment
  21. 2026-09-26 14:33 UTCEG score recompute
  22. 2026-09-26 13:38 UTCEG score recompute
  23. 2026-09-26 13:30 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-100656?
CVE-2026-100656 is a high vulnerability published on September 26, 2026. Netty (io.netty:netty-codec-http) contains an unbounded per-connection queue growth flaw in HttpServerCodec. The codec tracks the HTTP method of each still-unanswered pipelined request; the first 32 entries are bit-packed into a single long, but every additional entry is appended to…
When was CVE-2026-100656 disclosed?
CVE-2026-100656 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-2026-100656 actively exploited?
CVE-2026-100656 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.4% probability of exploitation in the next 30 days (34th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-100656?
CVE-2026-100656 has a CVSS base score of 7.5 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-100656?
A fix for CVE-2026-100656 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-100656 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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