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.

CVSS 3.1

7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS

0.9% chance of exploitation in the next 30 days; higher than 58% of CVEs (scores of 2026-10-25)

CWEs

CWE-415, CWE-1341

Published

2026-05-07

Modified

2026-10-26

Record from

the NVD, synced 2026-10-26

Affected

• golang:go

Packages (OSV)

References

• 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
• https://access.redhat.com/errata/RHSA-2026:22112

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