CVE-2026-44649

CRITICALPre-NVD 9.89.8—
EchelonGraph scoreMEDIUM confidence

This critical-severity CVE scores 9.8 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.2%, top 88% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
Elevated
9.8
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 0%CVSS: 9.8Exploit: NoneExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

SillyTavern is a locally installed user interface that allows users to interact with text generation large language models, image generation engines, and text-to-speech voice models. Prior to 1.18.0, SillyTavern accepts Remote-User (Authelia) and X-Authentik-Username (Authentik) HTTP headers to automatically log in users when SSO is configured. There is no validation that these headers originate from a trusted reverse proxy. Any network client that can reach the SillyTavern port directly can inject these headers and authenticate as any user, including administrators, without a password. This vulnerability is exploitable only when sso.autheliaAuth: true or sso.authentikAuth: true is set in config.yaml (both default to false). This vulnerability is fixed in 1.18.0.

CVSS v3
9.8
EG Score
9.8(medium)
EPSS
12.2%
KEV
Not listed

Published

May 29, 2026

Last Modified

June 2, 2026

Advisory Details (1)

Auto-updated Jun 20, 2026
🔬 Proof of concept available. Patch available. Sources: github.
github Patch Available🟡 PoC Available

Authentication Bypass via SSO Header Injection · Advisory · SillyTavern/SillyTavern · GitHub

https://github.com/SillyTavern/SillyTavern/security/advisories/GHSA-gxx6-h3g6-vwjh

Vendor Advisories for CVE-2026-44649(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Affected Packages

(1 across 1 ecosystem)
npm(1)
PackageVulnerable rangeFixed inDependents
sillytavern—1.18.0—

Weakness Classification(4)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 11× in last 7d / 89× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

Showing the most recent 100 of 199 total refreshes for this CVE.

  1. 2026-07-15 16:57 UTCEPSS rescore
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  3. 2026-07-14 18:29 UTCEG score recompute
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  1. 2026-07-01 15:07 UTCEPSS rescore
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  75. 2026-06-14 03:29 UTCEG score recompute

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-44649?
CVE-2026-44649 is a critical vulnerability published on May 29, 2026. SillyTavern is a locally installed user interface that allows users to interact with text generation large language models, image generation engines, and text-to-speech voice models. Prior to 1.18.0, SillyTavern accepts Remote-User (Authelia) and X-Authentik-Username (Authentik) HTTP headers to…
When was CVE-2026-44649 disclosed?
CVE-2026-44649 was first published in the National Vulnerability Database on May 29, 2026, with the most recent update on June 2, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-44649 actively exploited?
CVE-2026-44649 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 12.2% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-44649?
CVE-2026-44649 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2026-44649?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-44649, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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