[UPDATE] [high] Netty: Multiple vulnerabilities

CSIRTS triage

What

Multiple vulnerabilities allow a remote, anonymous attacker to bypass security measures, manipulate data, disclose confidential information, or cause a denial-of-service condition.

Who is affected

Deployments of Netty.

Urgency

Remediation is high urgency due to the severity and potential for exploitation.

Action

Update to the latest version of Netty.

AI-assisted analysis generated from the source advisory — verify against the original.

Details

Source

CERT-Bund (BSI) Security Advisories (DE · national-cert · site)

Severity

high

Published

2026-08-13

Exploitation

Not in CISA KEV at last sync

Language

Machine-translated to English — verify against the original

Original advisory: https://wid.cert-bund.de/portal/wid/securityadvisory?name=WID-SEC-2026-1814

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

• Low exploitation riskCVE-2026-500090.20% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 11% of all EPSS-scored CVEs.
• Moderate exploitation riskCVE-2026-442491.0% 30-day exploitation probability. Patch within normal cadence, watch for KEV listing. Riskier than 60% of all EPSS-scored CVEs.
• Low exploitation riskCVE-2026-442500.46% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 38% of all EPSS-scored CVEs.
• Low exploitation riskCVE-2026-448900.46% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 38% of all EPSS-scored CVEs.
• Low exploitation riskCVE-2026-448920.28% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 20% of all EPSS-scored CVEs.
• Low exploitation riskCVE-2026-448930.62% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 47% of all EPSS-scored CVEs.
• Low exploitation riskCVE-2026-448940.14% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 4% of all EPSS-scored CVEs.
• Low exploitation riskCVE-2026-454160.86% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 55% of all EPSS-scored CVEs.
• Low exploitation riskCVE-2026-455360.14% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 3% of all EPSS-scored CVEs.
• Low exploitation riskCVE-2026-456730.26% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 17% of all EPSS-scored CVEs.

Referenced CVEs

Same CVEs, other sources

How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.

• unknownNCSC-2026-0325 [1.00] [M/H] Vulnerabilities patched in Atlassian productsncsc-nl
• unknownexploitedMultiple vulnerabilities in IBM products (August 21, 2026)cert-fr-avis
• highexploited[NEW] [high] Atlassian Products (Bamboo, Bitbucket, Confluence, Crucible, Fisheye, and Jira): Multiple vulnera…cert-bund
• high[NEW] [high] Atlassian Bamboo, Bitbucket, Confluence, Fisheye, Crucible, Jira and Jira Service Management: Mul…cert-bund
• unknownexploitedMultiple vulnerabilities in IBM products (August 14, 2026)cert-fr-avis
• unknownMultiple vulnerabilities in IBM products (July 24, 2026)cert-fr-avis
• unknownMultiple vulnerabilities in IBM products (July 17, 2026)cert-fr-avis
• highGHSA-4grm-h2qv-h6w6: Netty HTTP/3 QPACK Blocked Streams Memory Exhaustionghsa
• highGHSA-h2qv-fj59-j46j: Netty HAProxy: Unbalanced Reference Count in Nested PP2_TYPE_SSL TLV Parsing Leads to Mem…ghsa
• mediumGHSA-c2gf-v879-257j: netty-codec-http2: ByteBuf Reference-Count Leak in DelegatingDecompressorFrameListener Le…ghsa
• highGHSA-6jv9-x5w9-2ccm: Netty's Lack of Lifecycle Cleanup Leads to Pooled ByteBuf Leak in RedisArrayAggregatorghsa
• highGHSA-5pvg-856g-cp85: Netty has Insufficient Bailiwick Validation for NS Recordsghsa

Recent advisories for Netty

A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.

• medium[NEW] [medium] Netty: Multiple vulnerabilitiescert-bund · 2026-08-25
• lowCVE-2026-76816: Netty is an asynchronous, event-driven network application framework. Prior to versions 4.1.13…nvd · 2026-08-24
• unknownCVE-2026-62380: Netty (io.netty:netty-codec-socks) versions 4.2.0.Final through 4.2.16.Final and 4.1.x through…nvd · 2026-08-22
• highCVE-2026-62243: Netty (io.netty:netty-handler) versions from 4.2.0.Final through 4.2.16.Final and versions thr…nvd · 2026-08-22
• highGHSA-4899-mpch-38p3: netty-incubator-codec-ohttp BinaryHttpParser: Unauthenticated CPU-exhaustion DoS via infi…ghsa · 2026-08-20
• highGHSA-hmq9-67w8-j5pw: netty-incubator-codec-ohttp: BinaryHttpParser should enforce limits for variable lengths …ghsa · 2026-08-20

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