SillyTavern: Incomplete IP validation in /api/search/visit allows SSRF via localhost and IPv6

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

5.0 · CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N

EPSS

• CVE-2026-34526: 0.22% estimated exploitation activity in the next 30 days; percentile 12.18 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Details Distinct from CVE-2025-59159 and CVE-2026-26286 (all fixed in v1.16.0). This endpoint is still unpatched. In src/endpoints/search.js line 419, the hostname is checked against /^\d+\.\d+\.\d+\.\d+$/. This only matches literal dotted-quad IPv4 (e.g. 127.0.0.1, 10.0.0.1). It does not catch: - localhost (hostname, not dotted-quad) - [::1] (IPv6 loopback) - DNS names resolving to internal addresses (e.g. localtest.me - 127.0.0.1) A separate port check (urlObj.port !== '') limits exploitation to services on default ports (80/443), making this lower severity than a fully unrestricted SSRF. PoC 1. Start SillyTavern v1.16.0 normally 2. Send requests to compare blocked vs bypassed (requires a valid session cookie or CSRF disabled): The 400 vs 500 difference confirms localhost and [::1] pass the IP check. The 500 is ECONNREFUSED (nothing listening on port 80), not a validation rejection. Impact Server-side request forgery with partial restrictions. An authenticated user can force the…

Published by the source

1 Apr 2026, 21:42 UTC

Last modified by the source

6 Apr 2026, 17:37 UTC

Source last checked

26 Oct 2026, 12:47 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-wm7j-m6jm-8797

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-wm7j-m6jm-8797

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# Patch Next advisory brief: CVE-2026-34526

Advisory: SillyTavern: Incomplete IP validation in /api/search/visit allows SSRF via localhost and IPv6
IDs: CVE-2026-34526, GHSA-wm7j-m6jm-8797
Record: https://patchnext.com/advisories/cve-2026-34526 (revision 2, source checked 26 Oct 2026, 12:47 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 5.0)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: sillytavern 1.17.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm sillytavern: affected <= 1.16.0; fixed in 1.17.0

## Suggested inspection (read-only)
- `npm ls sillytavern --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on sillytavern.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-wm7j-m6jm-8797 (OSV record GHSA-wm7j-m6jm-8797 lists affected ranges: npm sillytavern >=0 <1.17.0 (fixed))
- Verified: https://github.com/advisories/GHSA-wm7j-m6jm-8797 (GitHub-reviewed advisory GHSA-wm7j-m6jm-8797 lists affected ranges: npm sillytavern >=0 <=1.16.0)

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