LobeHub Chat CVE-2026-120315

Requires a LobeChat server-database deployment (not the lightweight client-only mode) and an authenticated user session (CVSS PR:L). The concrete trigger is: supplying an unsanitized filename containing '../' sequences to the file.createFile tRPC procedure (which stores it in the files.name DB column), then invoking document parsing (document.parseFileContent / DocumentService.parseFile), which passes file.name unsanitized into path.join() inside writeTempFile(). Exploitation is limited to files writable by the application user, and RCE specifically requires overwriting a file that is subsequently executed/loaded (e.g. startServer.js on container restart, a dynamically loaded Node module, or a cron/SSH file) - so code execution is not instantaneous and may depend on a restart or load event. Limiting factors: valid authentication is needed, though this is substantially weakened in multi-tenant deployments (any tenant user can reach RCE/DoS) and in deployments with self-registration enabled (attacker registers to obtain the required session).

This is a genuine high-priority issue, not an inflated high-CVSS score. The supplied CVSS 4.0 vector (AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H) describes a network-reachable, low-complexity attack requiring only low privileges (PR:L = an authenticated user) with no user interaction and full compromise of confidentiality, integrity and availability - consistent with the described path-traversal arbitrary file write leading to RCE/DoS. The vuln.today decision label is 'this_week', reported by VulnCheck, which aligns with a serious but authentication-gated flaw rather than an emergency mass-exploitation event. No EPSS score and no CISA KEV status were provided, so there is no signal of confirmed active exploitation or statistically modeled exploitation probability; absence of these is not evidence of safety. A detailed public PoC (step-by-step HTTP requests plus a video) is published in the GitHub Security Advisory, which materially raises practical exploitability. The main mitigating factor is the PR:L authentication requirement, but the advisory notes this collapses in multi-tenant deployments (any user can reach RCE) and effectively disappears where self-registration is enabled (attacker registers, then exploits). Net: real priority for server-database LobeChat deployments, especially multi-tenant or open-registration ones.

An authenticated user (or, where self-registration is enabled, an attacker who simply registers) uploads a file, then calls file.createFile with a filename set to a path-traversal payload such as '../../../../../../app/startServer.js' and triggers document parsing, causing writeTempFile() to overwrite that application file with attacker-controlled content; on the next container/app restart the malicious code executes, yielding RCE (or a permanent crash loop for DoS). A detailed public PoC including HTTP requests and a video demonstration is published in the GitHub Security Advisory, making this straightforward to reproduce.