Is CVE-2026-44649 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-44649 being exploited in the wild.

How severe is CVE-2026-44649?

Critical severity, with a CVSS score of 9.8, published 29 May 2026.

Which products and versions are affected?

sillytavern (npm) <= 1.17.0, SEMVER:introduced=0,fixed=1.18.0.

Is there a fix for CVE-2026-44649?

Yes. sillytavern (npm): upgrade to 1.18.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-44649 attacked?

It is attacked over the network, in a network appliance.

Am I affected by CVE-2026-44649?

Check whether you run sillytavern (npm) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-44649: SillyTavern authentication bypass via SSO header injection

Q: Which products and versions are affected?

sillytavern (npm) <= 1.17.0, SEMVER:introduced=0,fixed=1.18.0.

Q: Is there a fix for CVE-2026-44649?

Yes. sillytavern (npm): upgrade to 1.18.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

Q: How is CVE-2026-44649 attacked?

It is attacked over the network, in a network appliance.

Q: Am I affected by CVE-2026-44649?

Check whether you run sillytavern (npm) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-44649 · Severity: critical · CVSS 9.8 · Published 2026-05-29

SillyTavern, an interface for interacting with text generation AI, contains a flaw in how it handles Single Sign-On (SSO) logins. An attacker can bypass security controls by sending specially crafted network requests that impersonate any user, including administrators. This could lead to a full account takeover, allowing unauthorized access to private data and administrative settings.

Technologies: sillytavern (npm). Vendors: npm.

Quick answers

Is CVE-2026-44649 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-44649 being exploited in the wild.
How severe is CVE-2026-44649?: Critical severity, with a CVSS score of 9.8, published 29 May 2026.
Which products and versions are affected?: sillytavern (npm) <= 1.17.0, SEMVER:introduced=0,fixed=1.18.0.
Is there a fix for CVE-2026-44649?: Yes. sillytavern (npm): upgrade to 1.18.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-44649 attacked?: It is attacked over the network, in a network appliance.
Am I affected by CVE-2026-44649?: Check whether you run sillytavern (npm) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

sillytavern (npm): upgrade to 1.18.0 or later
```
npm install sillytavern@1.18.0
```

Technical details

SillyTavern implements header-based SSO for Authelia and Authentik using the 'Remote-User' and 'X-Authentik-Username' headers. The application fails to validate that these headers originate from a trusted reverse proxy, allowing any client with network access to the SillyTavern port to inject them. Furthermore, a user enumeration vulnerability in the '/api/users/list' endpoint allows unauthenticated attackers to discover valid usernames to target. By combining these, an attacker can obtain an authenticated session for any user, including administrators. The issue is fixed in version 1.18.0 by introducing an IP allowlist for SSO headers.

Affected products

SillyTavern SillyTavern <= 1.17.0

Identifiers

CVE-2026-44649
GHSA-gxx6-h3g6-vwjh

Timeline

2026-05-11: disclosed
2026-05-11: patched: Fixed in version 1.18.0
2026-05-12: advisory

References

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