CVE-2026-33811

high

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.

References

https://pkg.go.dev/vuln/GO-2026-4981

https://groups.google.com/g/golang-announce/c/qcCIEXso47M

https://go.dev/issue/78803

https://go.dev/cl/767860

Details

Source: Mitre, NVD

Published: 2026-05-07

Updated: 2026-05-08

Risk Information

CVSS v2

Base Score: 7.8

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:C

Severity: High

CVSS v3

Base Score: 7.5

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

Severity: High

EPSS

EPSS: 0.00007