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.
Affected products
golang: go
References10
- pkg.go.dev/vuln/GO-2026-4981 Vendor Advisory
- go.dev/cl/767860 Patch
- go.dev/issue/78803 Issue Tracking
- groups.google.com/g/golang-announce/c/qcCIEXso47M Mailing ListThird Party Advisory
- access.redhat.com/errata/RHSA-2026:22112
- access.redhat.com/errata/RHSA-2026:22120
- access.redhat.com/errata/RHSA-2026:22121
- access.redhat.com/errata/RHSA-2026:23262
- access.redhat.com/errata/RHSA-2026:23264
- access.redhat.com/errata/RHSA-2026:33120
Metrics
- CVSS 3.1
-
7.5
HIGH
Score source: NVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - EPSS — exploit probability
- 1% percentile: 59 · as of 13 November 2026
- CWE
- CWE-415CWE-1341
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