CVE-2026-121611
Description
A flaw was found in GStreamer's gst-plugins-bad package. A use of uninitialized memory vulnerability exists in the H.265 (HEVC) bitstream parser when processing Video Parameter Sets that declare more than one HRD (Hypothetical Reference Decoder) parameter set. A remote attacker could exploit this by providing a crafted H.265 media file or stream that, when processed by an application using GStreamer, causes unpredictable parser behavior and may crash the application. This can lead to a denial of service for any application using GStreamer to play back H.265 content.
Statement
GStreamer gst-plugins-bad (shipped in Red Hat products as gstreamer1-plugins-bad-free) is affected by this flaw in versions from 1.16.0 through versions prior to the upstream fix in 1.28.9. An attacker could cause a denial of service by supplying a crafted H.265 media file or stream processed by an application using the affected library.
Mitigation
No mitigation is currently available that meets Red Hat Product Security's standards for usability, deployment, applicability, or stability.
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 | 6.5 | N/A | N/A |
| Attack Vector | Network | N/A | N/A |
| Attack Complexity | Low | N/A | N/A |
| Privileges Required | None | N/A | N/A |
| User Interaction | Required | N/A | N/A |
| Scope | Unchanged | N/A | N/A |
| Confidentiality | None | N/A | N/A |
| Integrity Impact | None | N/A | N/A |
| Availability Impact | High | N/A | N/A |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
Red Hat CVSS v3 Score Explanation
Network-reachable via streaming; user must play crafted content; impact is crash/DoS only, no code execution demonstrated
Understanding the Weakness (CWE)
Confidentiality,Integrity,Availability,Other
Technical Impact: Varies by Context; Read Application Data
Uninitialized variables usually contain junk, which can not be trusted for consistency. Depending on the context, uninitialized variables could lead to denial of service conditions, or modify control flow in unexpected ways. They could also contain sensitive information that could be leaked if the variable is used in output. In some cases, an attacker can "pre-initialize" the variable using previous actions - i.e., control the contents of the variable - which might enable code execution.
Availability
Technical Impact: Alter Execution Logic; Unexpected State
This can cause a race condition if a lock variable check passes when it should not.
Authorization,Other
Technical Impact: Varies by Context
Strings that are not initialized are especially dangerous, since many functions expect a null at the end -- and only at the end -- of a string.
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