What’s Vulnerable › Vulnerabilities

CVE-2026-46600: Parsing an invalid SVCB or HTTPS RR can panic in golang.org/x/net/dns/dnsmessage

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.5% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-07-21 · updated 2026-10-24
• Weakness: CWE-125

Description

Parsing an invalid SVCB or HTTPS RR can panic when the size of a parameter value overflows the message buffer.

Affected products

• Golang.Org/X/Net: before 0.56.0 — fixed in 0.56.0
• Go Stdlib: from 1.26.0-0 before 1.26.6; from 1.27.0-0 before 1.27.0-rc.3 — fixed in 1.26.6, 1.27.0-rc.3
• golang.org/x/net/dns/dnsmessage: before 0.56.0 — fixed in 0.56.0
• golang.org/x/net/html: from 1.26.0-0 before 1.26.6; from 1.27.0-0 before 1.27.0-rc.3 — fixed in 1.26.6, 1.27.0-rc.3

How to fix

Upgrade to a fixed version: Golang.Org/X/Net 0.56.0; Go Stdlib 1.26.6, 1.27.0-rc.3; golang.org/x/net/dns/dnsmessage 0.56.0; golang.org/x/net/html 1.26.6, 1.27.0-rc.3. Check the vendor advisory for mitigations.

References

• https://go.dev/cl/786345
• https://go.dev/issue/79795
• https://groups.google.com/g/golang-announce/c/94pEornpRlI
• https://pkg.go.dev/vuln/GO-2026-5942

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