CVE-2026-53701
Description
An out-of-bounds write vulnerability was found in GStreamer's H.266/VVC PPS picture partition parser in gst-plugins-bad. In the multi-slice-in-tile processing of gst_h266_parser_parse_picture_partition() (gsth266parser.c), the loop iterates without checking that the slice index stays within bounds, writing past three fixed-size arrays (slice_height_in_ctus, slice_top_left_ctu_x, slice_top_left_ctu_y) in the GstH266PPS structure. While the initial proof-of-concept demonstrated a 4-byte out-of-bounds write, the code permits larger writes across multiple iterations. A crafted H.266/VVC media file can trigger this vulnerability.
Statement
The H.266/VVC codec parser is part of gst-plugins-bad and is available in GStreamer 1.26 and later. Older versions of GStreamer shipped in Red Hat Enterprise Linux do not include H.266 support and are not affected. The upstream maintainer confirmed the out-of-bounds write is bounded within preallocated structure arrays and did not cause crashes in testing. Practical exploitation for code execution is considered unlikely with modern hardening such as ASLR and stack protectors.
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base 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
Out-of-bounds write in H.266/VVC PPS parser. Write is bounded within preallocated structure arrays. No demonstrated crash or code execution.
Understanding the Weakness (CWE)
Integrity
Technical Impact: Modify Memory; Execute Unauthorized Code or Commands
Write operations could cause memory corruption. In some cases, an adversary can modify control data such as return addresses in order to execute unexpected code.
Availability
Technical Impact: DoS: Crash, Exit, or Restart
Attempting to access out-of-range, invalid, or unauthorized memory could cause the product to crash.
Other
Technical Impact: Unexpected State
Subsequent write operations can produce undefined or unexpected results.
Acknowledgements
Red Hat would like to thank Tianshuo Han for reporting this issue.
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