CVE-2026-121629
Description
A flaw was found in GStreamer's adaptive streaming demuxers (HLS, DASH, MSS). When processing a media playlist or manifest, URIs referenced in the manifest content are fetched without restricting which URI schemes are permitted. An attacker who controls a manifest URL, or who can inject content into an HTTP manifest response, can include file:// URIs pointing to arbitrary local files, causing the affected application to read and process those files. In automated or server-side deployments such as media recorders, proxies, and downloaders, this can lead to disclosure of sensitive local files. Existence of files can also be inferred through differing error responses even when content is not directly observable.
Statement
This vulnerability is rated Important because a remote party who can supply or influence an adaptive streaming manifest can cause GStreamer to read local files available to the process, with high confidentiality impact where pipeline output is stored or forwarded.
Supported RHEL 10.2 and later streams and RHIVOS 2.1 ship gstreamer1-plugins-good 1.26.x or newer, which includes the file:// read path introduced in upstream 1.26.0, and are affected. Fedora 43 ships 1.26.x and is affected. Fedora 44 and Rawhide ship 1.28.8, which remains below the upstream fix version 1.28.9, and are affected.
Supported RHEL 9 and earlier RHEL streams ship gstreamer1-plugins-good versions below 1.26.0. Those builds use a download path that cannot open file:// segment URLs from manifest content, so they are not affected by this issue.
Mitigation
Avoid opening HLS, DASH, or MSS manifests from untrusted network sources. Run GStreamer-based applications with minimal filesystem access using Linux namespaces or containers, restricting the process to only the directories it legitimately requires. Where feasible, use network controls to limit which manifest hosts the application may contact. These measures reduce risk but do not remove the vulnerability.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 7.5 | N/A | 7.5 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | None | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | High | N/A | High |
| Integrity Impact | None | N/A | None |
| Availability Impact | None | N/A | None |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Red Hat CVSS v3 Score Explanation
Network-delivered manifest can trigger local file read via file:// URIs in playlist content; no authentication required for automated pipelines.
Understanding the Weakness (CWE)
Integrity,Confidentiality
Technical Impact: Read Files or Directories
The application can operate on unexpected files, such as system files or configuration files. Confidentiality is violated when the targeted filename is not directly readable by the attacker.
Integrity,Confidentiality,Availability
Technical Impact: Modify Files or Directories; Execute Unauthorized Code or Commands
The application can operate on unexpected files. This may violate integrity if the filename is written to, or if the filename is for a program or other form of executable code.
Availability
Technical Impact: DoS: Crash, Exit, or Restart; DoS: Resource Consumption (Other)
The application can operate on unexpected files. Availability can be violated if the attacker specifies an unexpected file that the application modifies. Availability can also be affected if the attacker specifies a filename for a large file, or points to a special device or a file that does not have the format that the application expects.
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