CVE-2026-33811
HIGHCVSS 7.5/10EPSS 0.81%
Last modified
CVE-2026-33811 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. When using LookupCNAME with the cgo DNS resolver, a very long CNAME response can trigger a double-free of C memory and a crash.. EPSS estimates a 0.81% chance of exploitation in the next 30 days.
Description
When using LookupCNAME with the cgo DNS resolver, a very long CNAME response can trigger a double-free of C memory and a crash.
Metrics
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness Enumeration
Affected Software
| Vendor | Product | Versions |
|---|---|---|
| Golang | Go | < 1.25.10 |
| Golang | Go | >= 1.26.0, < 1.26.3 |
References
- https://go.dev/issue/78803Issue Tracking
- https://groups.google.com/g/golang-announce/c/qcCIEXso47MMailing List, Third Party Advisory
- https://pkg.go.dev/vuln/GO-2026-4981Vendor Advisory
Timeline
- Published
- Last Modified
- Status
- Modified
Frequently Asked Questions
What is CVE-2026-33811?
When using LookupCNAME with the cgo DNS resolver, a very long CNAME response can trigger a double-free of C memory and a crash.
How severe is CVE-2026-33811?
CVE-2026-33811 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 0.81% probability of exploitation in the next 30 days.
How do I fix CVE-2026-33811?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.
How Strix Helps
- How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
- Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
- PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
- AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.
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Are you affected by CVE-2026-33811?
Run a free Strix scan to check your systems for this vulnerability.
Scan your code nowSource: NVD / NIST