Advisory record · GHSA-mqxv-9rm6-w8qc

Ech0: ParseAcceptLanguage `_` separator bypass enables ~70x CPU amplification via Accept-Language header in i18n.Middleware

CVSS 4.0, no score published

Published by the GitHub Advisory Database at 14 Jul 2026, 19:58 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

Package	Ecosystem	Affected	Fixed in
github.com/lin-snow/ech0	Go	all versions	No fixed version yet

Identifiers: GHSA-mqxv-9rm6-w8qc · GO-2026-5981
Weakness (CWE): CWE-770 · CWE-772
Tags: Denial of service
Published: 14 Jul 2026
Updated: 21 Jul 2026

Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

Severity and exploitation

Score	Rating	CVSS	Vector	Source
Not published	None	4.0	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N	GitHub Advisory Database

CISA KEV Not listed.
EPSS No score.

Timeline

31 Oct 2026, 14:58 UTC First seen by agentprime
31 Oct 2026, 14:58 UTC Confirmed by OSV

Sources

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.