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CVE-2026-44892 netty CVE debrief

CVE-2026-44892 is a HIGH severity vulnerability in the Netty network application framework. The `Http3ConnectionHandler` in the Netty HTTP/3 codec has a default configuration that lacks an enforced maximum header size limit. When a peer does not specify `HTTP3_SETTINGS_MAX_FIELD_SECTION_SIZE`, the implementation defaults to an unbounded limit. This allows a malicious client or server to send an enormous number of headers, leading to a memory exhaustion Denial of Service via an `OutOfMemoryError`. The vulnerability has a CVSS score of 7.5 and was published on [cve-org](https://www.cve.org/CVERecord?id=CVE-2026-44892).

Vendor
netty
Product
Unknown
CVSS
HIGH 7.5
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's HTTP/3 codec, particularly those who have not upgraded to version 4.2.15.Final, should be aware of this vulnerability.

Technical summary

The default configuration of the `Http3ConnectionHandler` in Netty's HTTP/3 codec lacks an enforced maximum header size limit. This can be exploited by a malicious client or server to cause a Denial of Service via OutOfMemoryError.

Defensive priority

HIGH

Recommended defensive actions

  • Upgrade to Netty version 4.2.15.Final or later.
  • Review and adjust the configuration of the `Http3ConnectionHandler` to enforce a maximum header size limit.

Evidence notes

The vulnerability was patched in Netty version 4.2.15.Final. [ref-4](https://github.com/netty/netty/releases/tag/netty-4.2.15.Final) and [ref-5](https://github.com/netty/netty/security/advisories/GHSA-c2rx-5r8w-8xr2) provide additional information.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-44892 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-44892

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

  • CVE-2026-44892 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-44892

    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.