CVE-2026-44648 — sillytavern
HIGHCVE-2026-44648 is a high-severity (CVSS 7.5) CWE-613 vulnerability in sillytavern. A fix is available for sillytavern — see the affected versions and patch details below.
SillyTavern: Existing sessions are not invalidated after password change, allowing session reuse and account takeover
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
- A successful exploit gives an attacker total control of the affected component, not partial access.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-44648.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
sillytavernnpmDescription
Summary
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.
Impact
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.
Resolution
A fix was released in the version 1.18.0, invalidating a session cookie on account password change.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | sillytavern | all versions | 1.18.0npm install sillytavern@1.18.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for sillytavern, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update sillytavern to 1.18.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-44648 is resolved across your whole dependency graph.
Workarounds
Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.
Frequently Asked Questions
Is CVE-2026-44648 in your dependencies?
Find it across npm, including transitive dependencies.