CVE-2026-119727
Description
A flaw was found in GStreamer's gst-plugins-bad H.265 video parser. When parsing a specially crafted H.265 bitstream containing a Screen Content Coding (SCC) extension with certain palette predictor initializer settings, an integer underflow in the upper-bound computation allows the parser to accept an out-of-range value for the number of palette predictor entries. This causes the parser to write beyond the end of a fixed-size array, resulting in memory corruption and an application crash. An attacker can deliver the malformed bitstream as a local file or over a network stream such as HTTP, HLS, DASH, RTSP, RTP, or WebRTC. Successful exploitation requires the application to open or play that content, and is limited to a denial-of-service impact.
Statement
This vulnerability is rated as Moderate severity because exploitation causes a denial of service (application crash) when a user or process opens a crafted H.265 file or network stream; no confidentiality or integrity impact has been demonstrated. The H.265 parser is reachable from network streams such as HTTP, HLS, DASH, RTSP, RTP, and WebRTC, as well as from a local file. User interaction is required to open or play the content. The vulnerable code path requires H.265 SCC palette mode with predictor initializers present, which is uncommon in typical consumer video and needs a deliberately malformed bitstream.
Red Hat Enterprise Linux 7 and RHEL 8 ship gstreamer1-plugins-bad-free based on upstream GStreamer 1.10.x and 1.16.x respectively. Those upstream versions do not include the H.265 SCC palette predictor initializer parsing added in later GStreamer releases, so RHEL 7 and RHEL 8 are not affected.
RHEL 9, RHEL 10, and Red Hat In-Vehicle OS ship gstreamer1-plugins-bad-free versions below upstream fix 1.28.1 and are affected. Fedora 44 and Fedora rawhide ship versions that include the fix. Fedora 43 remains affected.
SELinux confinement of the media application may limit impact after a crash in confined deployments.
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 | 6.5 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | None | N/A | None |
| User Interaction | Required | N/A | Required |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | None | N/A | None |
| Integrity Impact | None | N/A | None |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
cve.org: 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-delivered H.265 file; user must trigger playback; crash = full DoS for the session
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Crash, Exit, or Restart; DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory)
Buffer overflows generally lead to crashes. Other attacks leading to lack of availability are possible, including putting the program into an infinite loop.
Integrity,Confidentiality,Availability,Access Control
Technical Impact: Execute Unauthorized Code or Commands; Bypass Protection Mechanism; Modify Memory
Buffer overflows often can be used to execute arbitrary code, which is usually outside the scope of a program's implicit security policy. Besides important user data, heap-based overflows can be used to overwrite function pointers that may be living in memory, pointing it to the attacker's code. Even in applications that do not explicitly use function pointers, the run-time will usually leave many in memory. For example, object methods in C++ are generally implemented using function pointers. Even in C programs, there is often a global offset table used by the underlying runtime.
Integrity,Confidentiality,Availability,Access Control,Other
Technical Impact: Execute Unauthorized Code or Commands; Bypass Protection Mechanism; Other
When the consequence is arbitrary code execution, this can often be used to subvert any other security service.
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