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CVE-2026-50560 netty CVE debrief

CVE-2026-50560 is a vulnerability in Netty, a network application framework. Prior to versions 4.1.135.Final and 4.2.15.Final, Netty's HTTP/2 max header size handling produces an attack similar to HTTP/2 Rapid Reset. The vulnerability is caused by the `SETTINGS_MAX_HEADER_LIST_SIZE` setting in the http2 specification. When a client sends this setting to Netty, it can cause Netty to behave in a way that is similar to the http2 reset attack, but with a different on-the-wire signature. Versions 4.1.135.Final and 4.2.15.Final patch the issue.

Vendor
netty
Product
Unknown
CVSS
MEDIUM 6.9
CISA KEV
Not listed in stored evidence
Original CVE published
2026-06-12
Original CVE updated
2026-06-15
Advisory published
2026-06-12
Advisory updated
2026-06-15

Who should care

Users of Netty prior to versions 4.1.135.Final and 4.2.15.Final should be aware of this vulnerability and take steps to upgrade to a patched version.

Technical summary

The vulnerability is caused by the `SETTINGS_MAX_HEADER_LIST_SIZE` setting in the http2 specification. When a client sends this setting to Netty, it can cause Netty to behave in a way that is similar to the http2 reset attack, but with a different on-the-wire signature.

Defensive priority

MEDIUM

Recommended defensive actions

  • Upgrade to Netty version 4.1.135.Final or 4.2.15.Final or later.
  • Review and adjust the `SETTINGS_MAX_HEADER_LIST_SIZE` setting in your Netty configuration.

Evidence notes

The CVE-2026-50560 vulnerability was published on [cve-org](https://www.cve.org/CVERecord?id=CVE-2026-50560) and has a CVSS score of 6.9. More information can be found on [nvd](https://nvd.nist.gov/vuln/detail/CVE-2026-50560).

Sources and references

Verified primary and authoritative sources

  • CVE-2026-50560 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-50560

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-50560 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-50560

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.