Cyber Resilience

CVE-2026-48059

Netty ≤ 4.1.135

Published
12 June 2026
Modified
13 August 2026
Patch / advisory
View advisory
CVSS Score v4 8.7
Click a component to see what it means
Raw vectorCVSS:4.0/AV:N/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
EPSS Score 0.0063 47th percentile
Risk Priority 45 floored blend · peak EPSS

Summary

CVE-2026-48059 is a high-severity Missing Release of Memory after Effective Lifetime (CWE-401) vulnerability in Netty Netty. Its CVSS base score is 8.7 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 47th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SI-10 (Information Input Validation) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

Netty is a network application framework for development of protocol servers and clients. Prior to versions 4.1.135.Final and 4.2.15.Final, the HAProxy PROXY protocol v2 codec in netty leaks native or heap memory on every connection when a client sends a…

more

syntactically valid header containing nested `PP2_TYPE_SSL` TLVs (type-length-value records) at depth two or greater. The leak occurs on the successful parse path — no exception is thrown, the message fires downstream, the decoder removes itself, and the application releases the `HAProxyMessage` normally. Yet the underlying cumulation buffer (a pooled, potentially direct `ByteBuf` allocated by the channel) remains permanently pinned. Versions 4.1.135.Final and 4.2.15.Final patch the issue.

CWE(s)
CWE-401CWE-1286

Related Threats

MITRE ATT&CK Enterprise Techniques

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
T1499 Endpoint Denial of Service Impact
Adversaries may perform Endpoint Denial of Service (DoS) attacks to degrade or block the availability of services to users.
attack.mitre.org →
T1499.003 Application Exhaustion Flood Impact
Adversaries may target resource intensive features of applications to cause a denial of service (DoS), denying availability to those applications.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-48006Same product: Netty Netty
CVE-2025-58057Same product: Netty Netty
CVE-2026-56819Same product: Netty Netty
CVE-2026-48043Same product: Netty Netty
CVE-2026-42579Same product: Netty Netty
CVE-2026-59901Same product: Netty Netty
CVE-2026-56816Same product: Netty Netty
CVE-2025-58056Same product: Netty Netty
CVE-2026-33870Same product: Netty Netty
CVE-2026-42584Same product: Netty Netty

Affected Assets

netty
netty
≤ 4.1.135 · 4.2.0 — 4.2.15

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V1.1.1
  • V1.4.2
  • V2.1.1
  • V2.2.2

Mitigating Controls (NIST 800-53 r5) AI

SA-11 Developer Testing and Evaluation good match

Developer testing and evaluation (static analysis, fuzzing, or runtime leak detection) directly finds missing deallocation.

SI-10 Information Input Validation good match

SI-10 requires validation of information inputs for correctness, directly stopping syntactic validation failures from being introduced or exploitable.

SA-15 Development Process, Standards, and Tools partial match

Requiring documented development standards and tools can mandate memory-management disciplines that avoid leaks at introduction.

SA-8 Security and Privacy Engineering Principles partial match

Engineering principles applied during development can require explicit resource-release patterns that stop memory leaks from being coded.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly enforce proper memory allocation/deallocation via coding standards, reviews, and tooling.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.29 Security testing in development and acceptance mostly match
finds

Security testing in development can detect unreleased memory, providing partial coverage of the weakness.

A.8.25 Secure development life cycle partial match
prevents

Secure development life cycle mandates memory-management practices that reduce missing-release defects.

A.8.26 Application security requirements partial match
prevents

Application security requirements can specify explicit memory-release rules, partially mitigating the weakness.

A.8.27 Secure system architecture and engineering principles partial match
prevents

Secure system architecture and engineering principles include resource-management guidelines that address memory leaks.

A.8.28 Secure coding partial match
prevents

Secure coding standards directly require proper allocation/deallocation, covering most of this weakness.

A.8.6 Capacity management partial match
finds

Capacity management may detect memory exhaustion symptoms but does not prevent the coding flaw.

References