Resource exhaustion in Netty
CVE-2026-73507
Netty is an asynchronous, event-driven network application framework. Prior to 4.1.136.Final and 4.2.16.Final, io.netty.handler.codec.xml.XmlFrameDecoder.decode() failed to preserve closing-tag parser state across invocations, so an unauthenticated remote attacker could trickle-feed repeated </ sequences that repeatedly rescanned the accumulated buffer and exhausted an EventLoop thread's CPU, causing denial of service with a maxFrameLength of 1 MB. This issue is fixed in versions 4.1.136.Final and 4.2.16.Final.
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: 0.008 (54.6th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 55th percentile — 54.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.005 · newest: 0.008 · change: +0.003
Affected products
- Netty — versions < 4.1.136.Final, >= 4.2.0.Final, < 4.2.16.Final
Weakness classification (CWE)
References
- github.com/netty/netty/commit/5b68c61f37aa4a3045cba624cbea239655c9003b (Patch)
- github.com/netty/netty/commit/bb2ff68a1fb71cb4b0eb9a9e17b66c52aff680c6 (Patch)
- github.com/netty/netty/releases/tag/netty-4.1.136.Final (Release Notes)
- github.com/netty/netty/releases/tag/netty-4.2.16.Final (Release Notes)
- github.com/netty/netty/security/advisories/GHSA-v74w-7mr3-4qg3 (Vendor Advisory)
Frequently asked questions
- What is CVE-2026-73507?
- CVE-2026-73507 is a high-severity vulnerability in Netty, classified under Uncontrolled Resource Consumption. CVSS score: 7.5/10. Published 2026-08-13.
- How severe is CVE-2026-73507?
- High severity. CVSS v3 base score is 7.5 out of 10.