{"id":"CVE-2026-79658","state":"PUBLISHED","title":"Ech0 before 5.0.1 Denial of Service via Accept-Language","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).","publishedAt":"2026-08-25T11:33:23.319Z","updatedAt":"2026-10-08T15:25:11.723Z","severity":{"score":8.7,"label":"High","version":"4.0","vector":"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","source":"VulnCheck"},"assigner":"VulnCheck","products":["lin-snow Ech0"],"affected":[{"vendor":"lin-snow","product":"Ech0","packageURL":"pkg:golang/github.com/lin-snow/ech0","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThan":"5.0.1","versionType":"semver"},{"version":"5.0.1","status":"unaffected","versionType":"semver"}]}],"references":["https://github.com/lin-snow/Ech0/security/advisories/GHSA-mqxv-9rm6-w8qc","https://www.vulncheck.com/advisories/ech0-before-denial-of-service-via-accept-language"],"weaknesses":["CWE-400"],"ingestedAt":"2026-10-29T20:13:07.220Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/79xxx/CVE-2026-79658.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-79658","state":"PUBLISHED","datePublished":"2026-08-25T11:33:23.319Z","dateUpdated":"2026-10-08T15:25:11.723Z","assignerShortName":"VulnCheck","assignerOrgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","dateReserved":"2026-08-25T11:09:11.171Z"},"containers":{"cna":{"title":"Ech0 before 5.0.1 Denial of Service via Accept-Language","descriptions":[{"lang":"en","value":"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)."}],"affected":[{"vendor":"lin-snow","product":"Ech0","packageURL":"pkg:golang/github.com/lin-snow/ech0","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThan":"5.0.1","versionType":"semver"},{"version":"5.0.1","status":"unaffected","versionType":"semver"}]}],"references":[{"url":"https://github.com/lin-snow/Ech0/security/advisories/GHSA-mqxv-9rm6-w8qc","tags":["vendor-advisory"],"name":"GitHub Security Advisory (GHSA-mqxv-9rm6-w8qc)"},{"url":"https://www.vulncheck.com/advisories/ech0-before-denial-of-service-via-accept-language","name":"VulnCheck Advisory: Ech0 before 5.0.1 Denial of Service via Accept-Language","tags":["third-party-advisory"]}],"metrics":[{"cvssV4_0":{"Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","Safety":"NOT_DEFINED","attackComplexity":"LOW","attackRequirements":"NONE","attackVector":"NETWORK","baseScore":8.7,"baseSeverity":"HIGH","exploitMaturity":"NOT_DEFINED","privilegesRequired":"NONE","providerUrgency":"NOT_DEFINED","subAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","userInteraction":"NONE","valueDensity":"NOT_DEFINED","vectorString":"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","version":"4.0","vulnAvailabilityImpact":"HIGH","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"NONE","vulnerabilityResponseEffort":"NOT_DEFINED"},"format":"CVSS"},{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"HIGH","baseScore":7.5,"baseSeverity":"HIGH","confidentialityImpact":"NONE","integrityImpact":"NONE","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.1"},"format":"CVSS"}],"problemTypes":[{"descriptions":[{"cweId":"CWE-400","lang":"en","description":"Uncontrolled Resource Consumption","type":"CWE"}]}],"providerMetadata":{"shortName":"VulnCheck","orgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","dateUpdated":"2026-10-08T15:25:11.723Z"},"datePublic":"2026-06-04T00:00:00.000Z","cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:ech0:ech0:*:*:*:*:*:*:*:*","versionEndExcluding":"5.0.1"}]}]}],"credits":[{"lang":"en","value":"tonghuaroot","type":"reporter"}],"x_generator":{"engine":"vulncheck-endgame"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-08-26T15:58:40.254630Z","id":"CVE-2026-79658","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-08-26T16:12:11.021Z"}}]}}}