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High severity · published May 7, 2026
CVE-2026-33811
Crash when handling long CNAME response in net
7.5
CVSS
0.9%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.9% · higher than 59% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
NE
net · Go standard library
before 1.25.10; 1.26.0-0 before 1.26.3 · source: vendor
GO
GO · Golang
before 1.25.10; 1.26.0 before 1.26.3 · source: NVD
CO
Compliance Operator 1 · Red Hat
All versions, or not specified · source: CISA
C4
Cryostat 4 on RHEL 9 · Red Hat
All versions, or not specified · source: CISA
LS
Logging Subsystem for Red Hat OpenShift 6.4 · Red Hat
All versions, or not specified · source: CISA
LS
Logging Subsystem for Red Hat OpenShift 6.5 · Red Hat
All versions, or not specified · source: CISA
LF
Logging for Red Hat OpenShift 6 · Red Hat
All versions, or not specified · source: CISA
LF
Logging for Red Hat OpenShift 6.2 · Red Hat
All versions, or not specified · source: CISA
MG
Multicluster Global Hub 1.4.5 · Red Hat
All versions, or not specified · source: CISA
MG
Multicluster Global Hub 1.6.5 · Red Hat
All versions, or not specified · source: CISA
MG
Multicluster Global Hub 1.7.0 · Red Hat
All versions, or not specified · source: CISA
OA
OpenShift API for Data Protection 1.3 · Red Hat
All versions, or not specified · source: CISA
Affected product
NE
net
Go standard library
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-33811
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-33811
Patch
https://go.dev/cl/767860
Issue Tracking
https://go.dev/issue/78803
Mailing List
https://groups.google.com/g/golang-announce/c/qcCIEXso47M
Vendor Advisory
https://pkg.go.dev/vuln/GO-2026-4981
access.redhat.com
https://access.redhat.com/errata/RHSA-2026:22112
access.redhat.com
https://access.redhat.com/errata/RHSA-2026:22120
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