RCE in Netty
CVE-2026-44892
Netty is a network application framework for development of protocol servers and clients. Prior to version 4.2.15.Final, the default configuration of the `Http3ConnectionHandler` in the Netty HTTP/3 codec lacks an enforced maximum header size limit. When a peer does not explicitly specify `HTTP3_SETTINGS_MAX_FIELD_SECTION_SIZE`, the implementation defaults to an unbounded limit. This insecure default configuration allows a malicious client or server to send an enormous number of headers, leading to a memory exhaustion Denial of Service via an `OutOfMemoryError`. Version 4.2.15.Final contains a patch.
Vulnerability class: DoS (Denial of Service)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.005 (39.5th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 40th percentile — 39.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.005 · change: +0.002
Affected products
- Netty — versions >= 4.2.0.Final, < 4.2.15.Final
Weakness classification (CWE)
References
- github.com/netty/netty/releases/tag/netty-4.2.15.Final (Release Notes)
- github.com/netty/netty/security/advisories/GHSA-c2rx-5r8w-8xr2 (Vendor Advisory)
Frequently asked questions
- What is CVE-2026-44892?
- CVE-2026-44892 is a high-severity vulnerability in Netty, classified under Uncontrolled Resource Consumption. CVSS score: 7.5/10. Published 2026-06-12.
- How severe is CVE-2026-44892?
- High severity. CVSS v3 base score is 7.5 out of 10.