Staging Environment: Content and features may be unstable or change without notice.
Advisory details: vulnrichment / CVE-2026-55831
Advisory ID vulnrichment/CVE-2026-55831
Aliases
Summary Netty is a network application framework for development of protocol servers and clients. Prior to 4.1.136.Final and 4.2.16.Final, Netty's SPDY SETTINGS decoder accepts a peer-declared SETTINGS entry count up to the 24-bit frame-length limit and materializes every unique setting ID in `DefaultSpdySettingsFrame`, allowing a remote SPDY/3.1 peer to send a syntactically valid roughly 2 MiB SETTINGS frame that creates 262144 map entries and amplifies network input into heap growth and ordered-map insertion work. This issue is fixed in versions 4.1.136.Final and 4.2.16.Final.
Status Published
Exploitability 0.5
Weighted Severity 0.0
Risk
Affected and Fixed Packages Package Details
Introduced and Fixed Package Commit Patches Package Commit Patches Details
Weaknesses (2)
System Score Found at
cvssv3.1 7.5
ssvc Track
No exploits are available.

No EPSS data available for this advisory.

Patch URL
There are no known patches.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Found at None
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none


Vector: SSVCv2/E:P/A:Y/T:P/P:M/B:A/M:M/D:T/2026-07-23T14:33:23Z/ Found at None

Vector: SSVCv2/E:P/A:Y/T:P/P:M/B:A/M:M/D:T/2026-07-23T14:33:23Z/

Decision: Track

Source URL: https://github.com/cisagov/vulnrichment/blob/develop/2026/55xxx/CVE-2026-55831.json

Source Advisory: vulnrichment/CVE-2026-55831

View SSVC decision tree
[{'Exploitation': 'poc'},
 {'Automatable': 'yes'},
 {'Technical Impact': 'partial'},
 {'Mission Prevalence': 'minimal'},
 {'Public Well-being Impact': 'material'},
 {'Mission & Well-being': 'medium'}]