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://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-33811.json

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

https://bugzilla.redhat.com/show_bug.cgi?id=2467822

https://access.redhat.com/security/cve/CVE-2026-33811

https://access.redhat.com/errata/RHSA-2026:36797

https://access.redhat.com/errata/RHSA-2026:36796

https://access.redhat.com/errata/RHSA-2026:36776

https://access.redhat.com/errata/RHSA-2026:36651

https://access.redhat.com/errata/RHSA-2026:36648

https://access.redhat.com/errata/RHSA-2026:36625

https://access.redhat.com/errata/RHSA-2026:36617

https://access.redhat.com/errata/RHSA-2026:36319

https://access.redhat.com/errata/RHSA-2026:36207

https://access.redhat.com/errata/RHSA-2026:35995

https://access.redhat.com/errata/RHSA-2026:35994

https://access.redhat.com/errata/RHSA-2026:35993

https://access.redhat.com/errata/RHSA-2026:35832

https://access.redhat.com/errata/RHSA-2026:34364

https://access.redhat.com/errata/RHSA-2026:34359

https://access.redhat.com/errata/RHSA-2026:34357

https://access.redhat.com/errata/RHSA-2026:33574

https://access.redhat.com/errata/RHSA-2026:33150

https://access.redhat.com/errata/RHSA-2026:33142

https://access.redhat.com/errata/RHSA-2026:33123

https://access.redhat.com/errata/RHSA-2026:33120

https://access.redhat.com/errata/RHSA-2026:23264

https://access.redhat.com/errata/RHSA-2026:23262

Details

Source: Mitre, NVD

Published: 2026-05-07

Updated: 2026-07-09

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