Vulnerability in Netty
CVE-2026-73508
Netty is an asynchronous, event-driven network application framework. Prior to 4.1.136.Final and 4.2.16.Final, io.netty.handler.codec.dns.AbstractDnsRecord, io.netty.handler.codec.dns.DefaultDnsRecordDecoder.decodeRecord(), and io.netty.handler.codec.dns.DnsCodecUtil.decompressDomainName() failed to release retained or newly allocated ByteBuf objects when IDN.toASCII() or encodeDomainName() rejected a malformed domain name, allowing unauthenticated remote DNS packets to leak direct memory incrementally until denial of service. This issue is fixed in versions 4.1.136.Final and 4.2.16.Final.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L.
EPSS exploit prediction
EPSS: 0.004 (29.6th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 30th percentile — 29.6% 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: 0.004 · change: +0.000
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-mfg7-5gfp-c4w3 (Vendor Advisory)
Frequently asked questions
- What is CVE-2026-73508?
- CVE-2026-73508 is a medium-severity vulnerability in Netty, classified under Missing Release of Resource after Effective Lifetime. CVSS score: 5.3/10. Published 2026-08-13.
- How severe is CVE-2026-73508?
- Medium severity. CVSS v3 base score is 5.3 out of 10.