signalk-server has SSRF via absolute signalk.appIcon URL in the app store icon fetcher

Exploitation

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

CVSS

4.2 · CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:N

EPSS

• CVE-2026-115752: 0.18% estimated exploitation activity in the next 30 days; percentile 7.02 (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.

Summary The app store icon code (`dist/appstore/icon-probe.js` around line 200 and `icon-bytes.js` around line 138) resolves a plugin's declared `signalk.appIcon`. Relative paths are pinned to the CDN, but an absolute http(s) URL is used as-is: the server fetches it, follows redirects, and stores any `image/*` response as the plugin's icon, which is then served to the admin UI. Unrelated to GHSA-q59x-jc9f-gfqf.

Affected signalk-server 2.33.0 (latest).

Reproduction The real dist modules driven directly, Docker with `--network none`; a local "internal" service on 127.0.0.1 logs requests: ``` [CONTROL relative] declared=../../icon.png resolved=null internal-service hits: [] stored: null [ATTACK absolute] declared=http://127.0.0.1:35013/latest/meta-data/iam resolved=http://127.0.0.1:35013/latest/meta-data/iam internal-service hits: ["GET /latest/meta-data/iam"] stored: .../icon-bytes/evil-plugin@1.0.0.png (70 bytes) [ATTACK redirect] declared=http://127.0.0.1:35013/redir…

Published by the source

30 Oct 2026, 22:57 UTC

Last modified by the source

30 Oct 2026, 23:15 UTC

Source last checked

31 Oct 2026, 06:00 UTC

1. Revision 2 · amended · 31 Oct 2026

   Amended from osv record GHSA-7wpf-ch8f-5f4x

2. Revision 1 · created · 30 Oct 2026

   Published from ghsa record GHSA-7wpf-ch8f-5f4x

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# Patch Next advisory brief: CVE-2026-115752

Advisory: signalk-server has SSRF via absolute signalk.appIcon URL in the app store icon fetcher
IDs: CVE-2026-115752, GHSA-7wpf-ch8f-5f4x
Record: https://patchnext.com/advisories/ghsa-7wpf-ch8f-5f4x (revision 2, source checked 31 Oct 2026, 06:00 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 4.2)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: signalk-server 2.34.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm signalk-server: affected >= 2.28.0-beta.2, < 2.34.0; fixed in 2.34.0

## Suggested inspection (read-only)
- `npm ls signalk-server --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 signalk-server.
- 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://github.com/advisories/GHSA-7wpf-ch8f-5f4x (GitHub-reviewed advisory GHSA-7wpf-ch8f-5f4x lists affected ranges: npm signalk-server >=2.28.0-beta.2 <2.34.0)
- Verified: https://osv.dev/vulnerability/GHSA-7wpf-ch8f-5f4x (OSV record GHSA-7wpf-ch8f-5f4x lists affected ranges: npm signalk-server >=2.28.0-beta.2 <2.34.0 (fixed))

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