CVE-2026-79658
Ech0 before 5.0.1 Denial of Service via Accept-Language
- State
- Published
- Severity
- 8.7 High
- Published
- Aug 25, 2026
- Updated
- Oct 8, 2026
- Reserved
- Aug 25, 2026
Description
Ech0 before 5.0.1 does not impose any size or shape limit on the Accept-Language header processed by its i18n middleware, which runs on every HTTP request. The header is passed unfiltered to go-i18n's NewLocalizer, which internally calls golang.org/x/text/language.ParseAcceptLanguage. The CVE-2022-32149 mitigation in x/text caps '-' characters but not '_' characters, which the parser aliases to '-', allowing quadratic-time parsing to be triggered with a large header (up to Go's default 1 MiB) built from underscore separators. An unauthenticated attacker can send such requests to consume roughly 1.5 seconds of CPU each, and concurrent requests can saturate a multi-core server (denial of service).
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 8.7 High | 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 | VulnCheck |
| 3.1 | 7.5 High | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H | VulnCheck |
Weaknesses
- CWE-400 Uncontrolled Resource Consumption
Affected Products
| Product | Versions |
|---|---|
Ech0lin-snow |
|
References
- GitHub Security Advisory (GHSA-mqxv-9rm6-w8qc)vendor-advisory
- VulnCheck Advisory: Ech0 before 5.0.1 Denial of Service via Accept-Languagethird-party-advisory
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