CVE-2026-84203

MemOS is a memory operating system for LLMs and AI agents. In deployments where authentication is enabled (AUTH_ENABLED=true) but the undocumented, defaultless INTERNAL_SERVICE_SECRET environment variable is unset, the is_internal_request() check in src/memos/api/middleware/auth.py fails open: os.getenv("INTERNAL_SERVICE_SECRET") returns None and a request omitting the X-Internal-Service header also yields None, so the comparison None == None evaluates true. The request is then treated as a trusted internal principal and granted scopes: ["all"]. As a result, an unauthenticated remote attacker can reach the admin API-key management endpoints to mint API keys for any user, enumerate keys, revoke keys, and generate a master key for persistent privileged access, as well as all data endpoints.

Memos through version 0.30.0 omits the 100.64.0.0/10 carrier-grade NAT address range from SSRF protection in its link-metadata fetcher, allowing unauthenticated attackers to bypass IP validation. Attackers can make the server request internal hosts in that range including cloud metadata services and read page titles and descriptions back.

The safeDialContext function in Memos' webhook dispatch resolves the target hostname via net.DefaultResolver.LookupHost and validates the resulting IPs against reserved ranges, but then dials net.JoinHostPort(host, port) using the original hostname rather than the already-validated IP address.

Memos' webhook URL validation function isReservedIP checks a candidate IP against a reservedCIDRs list that omits 0.0.0.0/8 and never calls ip.IsUnspecified, unlike the correctly implemented sibling function isInternalIP.

Cross Site Scripting vulnerability in usememos Memos v.0.26.0 allows a remote attacker to obtain sensitive information via the SANITIZE_SCHEMA, Memo Rendering Component, and Public/Private Memo View pages.