CVE-2026-44648: SillyTavern Existing Sessions Are Not Invalidated Vulnerability

HIGH
Advisory Identifier: GHSA-wmm3-h9qj-p5v6
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CVSS 7.5
CWE-613
Published
Advisory Summary

CVE-2026-44648 is a HIGH (CVSS 7.5) existing sessions are not invalidated vulnerability (CWE-613: Insufficient Session Expiration) affecting SillyTavern libraries in the npm ecosystem. The issue involves existing sessions are not invalidated after password change, allowing session reuse and account takeover. Remediation is available by upgrading affected packages to version 1.18.0.

CVE-2026-44648 at a Glance

CVE Identifier CVE-2026-44648
GHSA Identifier GHSA-wmm3-h9qj-p5v6
Severity HIGH
CVSS v3.1 Base Score 7.5
CWE Classification CWE-613: Insufficient Session Expiration
Affected Product SillyTavern
Package Ecosystem npm
Published Date
Last Updated

Security Impact

CVSS: 7.5

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H).

Attack Vector Network (AV:N)
Attack Complexity High (AC:H)
Privileges Required None (PR:N)
User Interaction Required (UI:R)
Scope Unchanged (S:U)
Confidentiality High (C:H)
Integrity High (I:H)
Availability High (A:H)

How to Fix CVE-2026-44648

To remediate this vulnerability, upgrade all affected SillyTavern dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

sillytavern fixed: 1.18.0 
npm install sillytavern@1.18.0
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

npm ls sillytavern

How to Check if You Are Affected

To determine whether your Node.js application is affected by CVE-2026-44648, inspect your project dependencies using npm:

npm ls sillytavern

Analyze the terminal output to locate any version of SillyTavern in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.18.0), your application is affected.

Note: The npm ls sillytavern command inspects dependencies declared in your package.json and lockfile; it does not perform automated runtime dynamic scanning.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-613: Insufficient Session Expiration, where according to wasc, "insufficient session expiration is when a web site permits an attacker to reuse old session credentials or session ids for authorization.". In SillyTavern, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### 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.

CVE-2026-44648 Affected SillyTavern Versions

1 component(s)
Fixed Versions:
1.18.0
Product / Package Ecosystem Affected Versions Fixed Version
sillytavern
npm/sillytavern
npm
< 1.18.0
1.18.0

References

GitHub Advisory / Wiki ADVISORY
https://github.com/SillyTavern/SillyTavern/security/advisories/GHSA-wmm3-h9qj-p5v6
NVD — CVE-2026-44648 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-44648
SillyTavern Source Repository REPOSITORY
https://github.com/SillyTavern/SillyTavern
SillyTavern Release RELEASE
https://github.com/SillyTavern/SillyTavern/releases/tag/1.18.0

Frequently Asked Questions

What is CVE-2026-44648?
CVE-2026-44648 is a security vulnerability in SillyTavern involving Existing sessions are not invalidated after password change, allowing session reuse and account takeover under CWE-613: Insufficient Session Expiration.
Which SillyTavern versions are affected?
Affected versions include releases prior to 1.18.0 across affected packages: sillytavern.
What version fixes CVE-2026-44648?
Upgrading to 1.18.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is sillytavern affected?
Yes, sillytavern is affected in releases prior to 1.18.0. Upgrade your dependency to 1.18.0 or later.
What is the CVSS score of CVE-2026-44648?
CVE-2026-44648 has a CVSS v3.1 base score of 7.5 (HIGH) with vector string CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H.
What CWE is associated with CVE-2026-44648?
CVE-2026-44648 is classified under CWE-613: Insufficient Session Expiration (According to WASC, "Insufficient Session Expiration is when a web site permits an attacker to reuse old session credentials or session IDs for authorization.").
How can I check npm dependencies for CVE-2026-44648?
Run the dependency tree command: 'npm ls sillytavern'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-wmm3-h9qj-p5v6",
  "modified" : "2026-06-09T10:32:03Z",
  "published" : "2026-05-12T22:23:20Z",
  "aliases" : [ "CVE-2026-44648" ],
  "summary" : "SillyTavern: Existing sessions are not invalidated after password change, allowing session reuse and account takeover",
  "details" : "### Summary\nChanging 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.\n\n### Details\nSillyTavern 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.\n\n### PoC\n1.Log into the same SillyTavern account from two different browsers (e.g., Chrome and Firefox private mode).\n2.In Chrome, change the account password under User Settings → Change Password.\n3.In Firefox, refresh the page or perform a protected action (e.g., view API keys).\n4.Expected: Firefox session should be invalidated and ask for login.\n5.Actual: Firefox remains fully authenticated, able to perform all actions as the targeted user.\n\n### Impact\nAn 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.\nThis nullifies the most common recovery measure against session theft.\nThe default cookie lifespan is 400 days, giving an attacker a very long exploitation window.\n\n### Resolution\nA fix was released in the version 1.18.0, invalidating a session cookie on account password change.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "sillytavern"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.18.0"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 1.17.0"
    }
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/SillyTavern/SillyTavern/security/advisories/GHSA-wmm3-h9qj-p5v6"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-44648"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/SillyTavern/SillyTavern"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/SillyTavern/SillyTavern/releases/tag/1.18.0"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-613" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-05-12T22:23:20Z",
    "nvd_published_at" : "2026-05-29T19:16:24Z"
  }
}