Affects Netty, a widely used networking library; could enable DNS-based MitM across apps.
CVE-2026-45674
Netty DNS CNAME bailiwick validation flaw in older versions.
Is CVE-2026-45674 being exploited?
Not confirmed. CVE-2026-45674 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.25% probability of exploitation in the next 30 days.
How severe is CVE-2026-45674?
CVE-2026-45674 is rated High with a CVSS score of 8.7. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-45674?
Yes. A fix has been recorded for CVE-2026-45674. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-45674 affect?
CVE-2026-45674 affects Netty 4.1.x < 4.1.135.Final, Netty 4.2.x < 4.2.15.Final. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-45674?
Upgrade to Netty 4.1.135.Final+ or 4.2.15.Final+
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Allows spoofed CNAMEs to bypass validation, enabling potential MitM or traffic redirection via DNS responses.
Immediate action required
- affected>= 4.2.0.Final and < 4.2.15.Final
- affected< 4.1.135.Final
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.