# CVE-2026-73508: Netty: Memory Leak in DNS Record Decoder via Malformed Domain Names

> CVE-2026-73508: Netty: Memory Leak in DNS Record Decoder via Malformed Domain Names. CVSS 5.3 (CVSS 3.1).

Canonical: https://rewindex.com/cve/CVE-2026-73508
Last updated: 2026-09-23T15:39:29Z

- Published: 2026-08-13 14:27 UTC · Updated: 2026-09-23 15:39 UTC · Assigner: GitHub\_M
- CVSS: 5.3 (CVSS 3.1) · Severity: Medium · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
- EPSS: 0.63%, 50th percentile (scored 2026-10-25)
- CISA KEV: no
- CWE: CWE-772

## Description

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.

## Affected vendors and products

- netty: netty

## Tracked companies

- [Bitbucket](https://rewindex.com/company/bitbucket.md)
- [Confluence](https://rewindex.com/company/confluence.md)

## References

- [CVE record on cve.org](https://www.cve.org/CVERecord?id=CVE-2026-73508)
- [NVD entry](https://nvd.nist.gov/vuln/detail/CVE-2026-73508)
- [https://github.com/netty/netty/commit/5b68c61f37aa4a3045cba624cbea239655c9003b](https://github.com/netty/netty/commit/5b68c61f37aa4a3045cba624cbea239655c9003b)
- [https://github.com/netty/netty/commit/bb2ff68a1fb71cb4b0eb9a9e17b66c52aff680c6](https://github.com/netty/netty/commit/bb2ff68a1fb71cb4b0eb9a9e17b66c52aff680c6)
- [https://github.com/netty/netty/releases/tag/netty-4.1.136.Final](https://github.com/netty/netty/releases/tag/netty-4.1.136.Final)
- [https://github.com/netty/netty/releases/tag/netty-4.2.16.Final](https://github.com/netty/netty/releases/tag/netty-4.2.16.Final)
- [https://github.com/netty/netty/security/advisories/GHSA-mfg7-5gfp-c4w3](https://github.com/netty/netty/security/advisories/GHSA-mfg7-5gfp-c4w3)

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_Sources: CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (https://www.cve.org/) This product uses data from the NVD API but is not endorsed or certified by the NVD. (https://nvd.nist.gov/) Known Exploited Vulnerabilities catalog from CISA. (https://www.cisa.gov/known-exploited-vulnerabilities-catalog) EPSS scores from FIRST (Exploit Prediction Scoring System). (https://www.first.org/epss/)_


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Canonical: https://rewindex.com/cve/CVE-2026-73508 · Markdown: https://rewindex.com/cve/CVE-2026-73508.md · JSON: https://rewindex.com/api/v1/cves/CVE-2026-73508 · Data licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) · Generated 2026-10-26T03:09:00.431Z