Cross-Site Scripting in webtorrent

Exploitation

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

CVSS

6.1 · CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

EPSS

• CVE-2019-15782: 1.47% estimated exploitation activity in the next 30 days; percentile 73.80 (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.

Versions of webtorrent prior to 0.107.6 are vulnerable to Cross-Site Scripting. webtorrent servers started with torrent.createServer() lists a torrent's title and files in the index page without sanitization. This allows attackers to execute arbitrary JavaScript in the victim's browser through files with names containing the malicious payload. The issue is mitigated due to the fact that the server only allows fetching data pieces from the torrent. Recommendation Upgrade to version 0.107.6 or later.

Published by the source

4 Sep 2019, 10:02 UTC

Last modified by the source

8 Nov 2023, 04:01 UTC

Source last checked

26 Oct 2026, 12:21 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-gjh4-fcv3-whpq

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-gjh4-fcv3-whpq

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# Patch Next advisory brief: CVE-2019-15782

Advisory: Cross-Site Scripting in webtorrent
IDs: CVE-2019-15782, GHSA-gjh4-fcv3-whpq
Record: https://patchnext.com/advisories/cve-2019-15782 (revision 2, source checked 26 Oct 2026, 12:21 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.1)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: webtorrent 0.107.6. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm webtorrent: affected < 0.107.6; fixed in 0.107.6

## Suggested inspection (read-only)
- `npm ls webtorrent --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 webtorrent.
- 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-gjh4-fcv3-whpq (OSV record GHSA-gjh4-fcv3-whpq lists affected ranges: npm webtorrent >=0 <0.107.6 (fixed))
- Verified: https://github.com/advisories/GHSA-gjh4-fcv3-whpq (GitHub-reviewed advisory GHSA-gjh4-fcv3-whpq lists affected ranges: npm webtorrent >=0 <0.107.6)

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