CVE-2026-44648

Changing a user’s password does not invalidate existing sessions, allowing an attacker with a stolen cookie to retain access even after the victim resets their password.

Details

SillyTavern relies on cookie-session for authentication, storing all session data (user handle, permissions) in a signed cookie. The endpoints POST /api/users/change-password and POST /api/users/recover-step2 only update the password hash in the database but do not expire current sessions. Because the session is stateless and stored entirely in the client cookie, there is no server-side mechanism to revoke a token once issued.

PoC

1.Log into the same SillyTavern account from two different browsers (e.g., Chrome and Firefox private mode).
2.In Chrome, change the account password under User Settings → Change Password.
3.In Firefox, refresh the page or perform a protected action (e.g., view API keys).
4.Expected: Firefox session should be invalidated and ask for login.
5.Actual: Firefox remains fully authenticated, able to perform all actions as the targeted user.

Resolution

A fix was released in the version 1.18.0, invalidating a session cookie on account password change.

An attacker who obtains a valid session cookie (via XSS, MITM, physical access, etc.) can continue using it indefinitely, even after the legitimate user changes their password.
This nullifies the most common recovery measure against session theft.
The default cookie lifespan is 400 days, giving an attacker a very long exploitation window.

CVE-2026-44648 has a CVSS score of 7.5 (High). The vector is network-reachable, no privileges required, and user interaction required. 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 (1.18.0); upgrading removes the vulnerable code path.

Kodem intelligence

1. What is CVE-2026-44648? CVE-2026-44648 is a high-severity security vulnerability in sillytavern (npm), affecting versions <= 1.17.0. It is fixed in 1.18.0.
2. How severe is CVE-2026-44648? CVE-2026-44648 has a CVSS score of 7.5 (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-2026-44648? sillytavern (npm) versions <= 1.17.0 is affected.
4. Is there a fix for CVE-2026-44648? Yes. CVE-2026-44648 is fixed in 1.18.0. Upgrade to this version or later.
5. Is CVE-2026-44648 exploitable, and should I be worried? Whether CVE-2026-44648 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-2026-44648 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-2026-44648? Upgrade sillytavern to 1.18.0 or later.