CVE-2026-79658
HighCVSS 7.5Exploitation Probability (EPSS)
Low risk21th percentile - higher than 21% of all known CVEs
Summary
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).
Risk Assessment
Risk of denial of service via CPU exhaustion on the server, potentially leading to service unavailability for users.
Recommendation
Upgrade Ech0 to version 5.0.1 or later. Additionally, consider limiting the Accept-Language header size at the server level or applying patches in x/text.
Other vulnerabilities in Ech0
See all- CVE-2026-79673Medium
Ech0 before 4.4.3 protects the PUT /user endpoint with the profile:read scope, a read-only scope, but allows write operations including password changes. An attacker with an admin's profile:read access token can change the admin's password and login to obtain an unrestricted session token that bypasses all scope enforcement.
- CVE-2026-79672Medium
Ech0 before 4.4.3 fails to enforce scope-based authorization on nine comment panel admin endpoints, allowing access tokens with minimal scopes to perform full comment moderation operations. Attackers with a limited-scope access token can list, approve, reject, delete comments, and modify comment system settings by directly accessing the unprotected panel endpoints.
- CVE-2026-79671Medium
Ech0 before version 4.4.3 contains a server-side request forgery vulnerability in the validateWebhookURL function (webhook_setting_service.go), which only validates literal IP addresses via net.ParseIP() and fails to reject hostnames that DNS-resolve to private or internal IPs (e.g., 169.254.169.254.nip.io). An attacker with admin privileges can create a webhook with such a hostname to bypass validation and cause the server to make requests to internal services, cloud metadata endpoints, and private network resources. The issue is fixed in 4.4.3.
- CVE-2026-79670Medium
Ech0 before 4.4.3 contains a stored cross-site scripting vulnerability in the file upload endpoint that validates Content-Type using only client-supplied headers without server-side inspection. Attackers with admin privileges can upload SVG or HTML files containing JavaScript that executes in the application origin when accessed by any user, enabling session hijacking and data exfiltration.
- CVE-2026-79669Medium
Ech0 before 4.4.3 lacks authorization checks on system log endpoints allowing any authenticated non-admin user to read and stream all server logs. Attackers can access historical logs and real-time log streams via GET /api/system/logs, GET /api/system/logs/stream, and WS /ws/system/logs to gather reconnaissance data including internal file paths, error stack traces, and application state.
- CVE-2026-79668Medium
Ech0 before 4.7.3 contains an authentication bypass vulnerability in the PUT /api/echo/like/:id endpoint that allows unauthenticated attackers to increment engagement metrics without identity verification or rate limiting. Attackers can send repeated requests to arbitrarily inflate the fav_count field for any known echo identifier, compromising the integrity of engagement metrics and social ranking systems.
- CVE-2026-79667High
Ech0 version 4.3.4 and earlier fails to reliably enforce scoped access token (least-privilege) restrictions on several privileged admin routes. Multiple privileged endpoints (e.g., /api/inbox, /api/panel/comments, /api/backup/export) omit scope checks and authorize based only on the user's admin role, and the backup export handler discards token scope metadata entirely. An attacker holding a deliberately limited (low-scope) admin access token can reach broader privileged functionality than intended, including reading the inbox and exporting a full database backup ZIP archive. Fixed in 4.4.3.
- CVE-2026-79666Medium
Ech0 before 4.4.3 fails to enforce administrator authorization on dashboard log endpoints, allowing any authenticated user to access system logs. Attackers with valid user sessions can query GET /api/system/logs and subscribe to SSE and WebSocket log streams to retrieve sensitive operational data including file paths, stack traces, and internal URLs.
- CVE-2026-79665High
Ech0 before 4.5.1 contains an authorization bypass vulnerability where session tokens skip scope validation in RequireScopes middleware, allowing logged-in non-admin users to access admin endpoints. Attackers can read system logs, visitor statistics, user emails, and subscribe to live WebSocket logs by sending authenticated session tokens to unprotected endpoints.
- CVE-2026-79664High
Ech0 before 4.7.3 fails to properly revoke access tokens created with never-expire option, allowing attackers to maintain perpetual authenticated access after token theft. Three independent revocation mechanisms fail: logout panics on nil ExpiresAt field, RevokeToken skips when remainTTL is zero, and admin delete does not blacklist the JTI, leaving stolen tokens cryptographically valid until JWT secret rotation.
Original NVD description (English source)
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).
Vulnerability data from NVD (NIST) · CISA KEV · EPSS

