Io.netty:netty resolver dns: Netty Vulnerable to DNS Cache Poisoning via Missing Bailiwick Checks in CNAME Records
Affects io.netty:netty-resolver-dnsSource GCVE Database
Not known to be exploited · CVSS 8.7 High : upgrade to 4.2.15.Final soon.
Data as of 29 Oct 2026, 19:04 UTC
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 21% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 4.2.15.Final, 4.1.135.Final
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:NExploitation evidence
Disclosed: evidence found.
CVE published 8 Jun 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: evidence found.
Public exploit code: GitHub proofs of concept
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), GitHub proofs of concept, the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.
What to do
Upgrade io.netty:netty-resolver-dns to 4.2.15.Final; io.netty:netty-resolver-dns to 4.1.135.Final.
Patches and advisories
- access.redhat.com/errata/RHSA-2026:65126 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:62260 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:54435 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:53806 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:53646 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:53645 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:53644 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:50085 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:49701 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:49700 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:48151 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:41951 (opens in a new tab)
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Mavenio.netty:netty-resolver-dns | Affected
| Fixed in
|
| Mavenio.netty:netty-resolver-dns | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
Description
### Summary Netty's DnsResolveContext fails to validate the origin (bailiwick) of CNAME records in DNS responses. ### Details In `io.netty.resolver.dns.DnsResolveContext#buildAliasMap`, the resolver processes the ANSWER section of a DNS response and blindly caches all CNAME records it finds. According to https://datatracker.ietf.org/doc/html/rfc5452#section-6 ``` Care must be taken to only accept data if it is known that the originator is authoritative for the QNAME or a parent of the QNAME. One very simple way to achieve this is to only accept data if it is part of the domain for which the query was intended. ``` ### Impact DNS Cache Poisoning (Bailiwick Bypass). Any application using Netty's DNS resolver is impacted.
References
- github.com/netty/netty/security/advisories/GHSA-676x-f7gg-47vc (opens in a new tab)
- nvd.nist.gov/vuln/detail/CVE-2026-45674 (opens in a new tab)
- security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-45674.json (opens in a new tab)
- github.com/netty/netty/releases/tag/netty-4.2.15.Final (opens in a new tab)
- github.com/netty/netty/releases/tag/netty-4.1.135.Final (opens in a new tab)
- github.com/netty/netty (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2488400 (opens in a new tab)
- access.redhat.com/security/cve/CVE-2026-45674 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:65126 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:62260 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:54435 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:53806 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:53646 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:53645 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:53644 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:50085 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:49701 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:49700 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:48151 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:41951 (opens in a new tab)