CVE-2026-100655

io.netty/netty-codec-http: Netty: Denial of Service via unbounded SPDY concurrent streams

Published Sep 26, 2026 CVSS 3.1 · 7.5 High EPSS n/a KEV · Not listed
Description
This CVE ID has been rejected as a duplicate.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Title Netty before 4.1.138.Final Denial of Service via SpdySessionHandler io.netty/netty-codec-http: Netty: Denial of Service via unbounded SPDY concurrent streams
Type Values Removed Values Added
Title io.netty/netty-codec-http: Netty: Denial of Service via unbounded SPDY concurrent streams Netty before 4.1.138.Final Denial of Service via SpdySessionHandler
Type Values Removed Values Added
Title Netty before 4.1.138.Final Denial of Service via SpdySessionHandler io.netty/netty-codec-http: Netty: Denial of Service via unbounded SPDY concurrent streams
Metrics cvssV4_0

{'score': 6.9, 'vector': 'CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X'}

ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description Netty (io.netty:netty-codec-http) versions up to and including 4.1.137.Final and from 4.2.0.Final through 4.2.17.Final accept an unlimited number of concurrent remote-initiated SPDY streams: SpdySessionHandler defaults localConcurrentStreams to Integer.MAX_VALUE and exposes no API to change it. A remote peer that opens a SPDY connection and sends millions of SYN_STREAM frames with FLAG_FIN=0 causes the server to allocate unbounded heap and direct memory, eventually triggering a JVM OutOfMemoryError and crashing the service. Fixed in 4.1.138.Final and 4.2.18.Final. This CVE ID has been rejected as a duplicate.
CPEs cpe:2.3:a:netty:netty:*:*:*:*:*:*:*:*
Metrics cvssV4_0

{'score': 6.9, 'vector': 'CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N'}

cvssV4_0

{'score': 6.9, 'vector': 'CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X'}

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description Netty (io.netty:netty-codec-http) versions up to and including 4.1.137.Final and from 4.2.0.Final through 4.2.17.Final accept an unlimited number of concurrent remote-initiated SPDY streams: SpdySessionHandler defaults localConcurrentStreams to Integer.MAX_VALUE and exposes no API to change it. A remote peer that opens a SPDY connection and sends millions of SYN_STREAM frames with FLAG_FIN=0 causes the server to allocate unbounded heap and direct memory, eventually triggering a JVM OutOfMemoryError and crashing the service. Fixed in 4.1.138.Final and 4.2.18.Final.
Title Netty before 4.1.138.Final Denial of Service via SpdySessionHandler
First Time appeared Netty
Netty netty
Weaknesses CWE-770
CPEs cpe:2.3:a:netty:netty:*:*:*:*:*:*:*:*
Vendors & Products Netty
Netty netty
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

cvssV4_0

{'score': 6.9, 'vector': 'CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N'}

Weaknesses

Sources

Status
REJECTED
Assigner
VulnCheck
Published
Updated
Sep 28, 2026, 8:59 PM
Reserved
Sep 26, 2026, 2:33 AM
Status
Rejected
Published
Sep 26, 2026, 2:16 PM
Modified
Sep 28, 2026, 10:17 PM
Severity
Important
Public date
Sep 26, 2026, 1:23 PM