PublicCVE

CVE-2026-100656

HIGH8.7Denial of service

Description

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 breakdown

CVSS 4.0
Attack Vector
Network
Attack Complexity
Low
Attack Requirements
None
Privileges Required
None
User Interaction
None
Confidentiality (Vulnerable System)
None
Integrity (Vulnerable System)
None
Availability (Vulnerable System)
High
Confidentiality (Subsequent System)
None
Integrity (Subsequent System)
None
Availability (Subsequent System)
None
CVSS 3.1
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

Affected products

Updated 21m ago · 8 sources