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HighVulnerabilityupdated 29 Oct 2026, 13:05 UTC

Netty: several flaws let attackers bypass checks and crash services

Netty is a networking library used by many Java applications. Attackers could get around security checks, tamper with requests, or overload services so they stop working.

Official source
SeverityHighVulnerability
Being exploited?UnclearNo reports either way yet
Fix available?UnclearNo fixed version published in the sources yet
How sure is this?Official sourceBacked by an official source

What happened

Multiple vulnerabilities in the Netty Java networking framework allow security bypass, request or header manipulation, certificate validation bypass, information disclosure and denial of service.

Why it is dangerous: Applications built on Netty could have their security controls skipped, data altered, or be made unavailable, affecting services that rely on them.

Are you affected?

You are affected if you run Java applications or services that use the Netty networking library in a vulnerable version.

Netty (affected versions not specified in the provided material)

What to do

  1. Identify which of your applications or services use Netty, including indirectly through other frameworks
  2. Check the BSI/CERT-Bund advisory and the Netty project for the fixed version and update to it
  3. Monitor for abnormal request behavior and service outages until patched

Timeline

  1. 26 Oct 2026, 12:31 UTC
    Publicly disclosed
  2. 26 Oct 2026, 12:31 UTC
    Reported by CERT-Bund (BSI) · CERT-Bund (BSI)
  3. 26 Oct 2026, 12:31 UTC
    Reported by CERT-Bund (BSI) · CERT-Bund (BSI)
  4. 26 Oct 2026, 12:39 UTC
    Picked up by Zero Radar
  5. 28 Oct 2026, 22:08 UTC
    Severity raised to high
  6. 29 Oct 2026, 12:56 UTC
    Reported by CERT-Bund (BSI) · CERT-Bund (BSI)

Sources 3 reports, oldest first

Official vendor, government CERT or advisory database

Technical details

ID
ZR-bc01d2fd · ZR-c60c00bd · ZR-a28f3252
Disclosed
26 Oct 2026, 12:31 UTC
On Zero Radar
26 Oct 2026, 12:39 UTC (9 min after disclosure)
Last change
29 Oct 2026, 13:05 UTC

The plain-language parts and the attack diagram were written by an AI model (anthropic/claude-haiku-5.5) from the sources above. Facts like versions, exploitation and dates come from the sources themselves. How Zero Radar works

Netty: several flaws let attackers bypass checks and crash services · Zero Radar