Streamlink has an arbitrary local file read via file:// URI in HLS and DASH

Exploitation

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

CVSS

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

EPSS

• CVE-2026-44353: 0.44% estimated exploitation activity in the next 30 days; percentile 37.99 (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 Streamlink's HLS and DASH parsers do not validate the URI scheme of segment entries and other resources. A remote .m3u8 HLS playlist or .mpd DASH manifest can list file:///path/to/file as a segment, and streamlink will read that local file and write its contents to the output stream. Confirmed on streamlink 8.3.0 (latest release at time of report). Description Segment URIs from an HLS playlist or DASH manifest are passed to the worker without any scheme check. The underlying HTTP session accepts file:// URIs, which resolve against the local filesystem. There is no scheme allowlist at the parser level, so any path readable by the streamlink process is treated as a valid segment. The attacker does not need local access to the victim. A playlist/manifest hosted on an attacker-controlled server, fetched by streamlink on the victim's machine, is enough to trigger the read. Impact A remote attacker hosting a malicious playlist/manifest can make any client running streamlink against…

Published by the source

11 May 2026, 14:28 UTC

Last modified by the source

9 Jun 2026, 00:00 UTC

Source last checked

26 Oct 2026, 13:45 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-hgqw-6m45-hw5f

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-hgqw-6m45-hw5f

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# Patch Next advisory brief: CVE-2026-44353

Advisory: Streamlink has an arbitrary local file read via file:// URI in HLS and DASH
IDs: CVE-2026-44353, GHSA-hgqw-6m45-hw5f
Record: https://patchnext.com/advisories/cve-2026-44353 (revision 2, source checked 26 Oct 2026, 13:45 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: streamlink 8.4.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI streamlink: affected <= 8.3.0; fixed in 8.4.0

## Suggested inspection (read-only)
- `python -m pip show streamlink`: prints the installed version. Run with the environment that serves production active.

## 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 streamlink.
- 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-hgqw-6m45-hw5f (OSV record GHSA-hgqw-6m45-hw5f lists affected ranges: PyPI streamlink >=0 <8.4.0 (fixed))
- Verified: https://github.com/advisories/GHSA-hgqw-6m45-hw5f (GitHub-reviewed advisory GHSA-hgqw-6m45-hw5f lists affected ranges: PyPI streamlink >=0 <=8.3.0)

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