CVE-2026-33811
Crash when handling long CNAME response in net
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.
INFO
Published Date :
May 7, 2026, 8:16 p.m.
Last Modified :
May 7, 2026, 8:38 p.m.
Remotely Exploit :
No
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-33811
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
Solution
- Update the DNS resolver to handle long CNAME responses correctly.
- Apply patches addressing the double-free memory issue.
- Test DNS resolution with extended CNAME records.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-33811.
| URL | Resource |
|---|---|
| https://go.dev/cl/767860 | |
| https://go.dev/issue/78803 | |
| https://groups.google.com/g/golang-announce/c/qcCIEXso47M | |
| https://pkg.go.dev/vuln/GO-2026-4981 |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-33811 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-33811
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-33811 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-33811 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by [email protected]
May. 07, 2026
Action Type Old Value New Value Added 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. Added Reference https://go.dev/cl/767860 Added Reference https://go.dev/issue/78803 Added Reference https://groups.google.com/g/golang-announce/c/qcCIEXso47M Added Reference https://pkg.go.dev/vuln/GO-2026-4981