PatchSiren cyber security CVE debrief
CVE-2026-53703 Red Hat CVE debrief
A vulnerability was found in the GStreamer RealMedia demuxer (gst-plugins-ugly). When processing a RealMedia (.rm) file, the demuxer parses MDPR (media properties) chunks to configure audio streams. For audio stream header versions 4 and 5, the parser reads fields such as codec type, packet size, sample rate, channel count, and extra codec data length from fixed offsets within the chunk without first checking that the chunk contains enough data. If a malicious file provides an MDPR chunk that is too small to contain a complete audio stream header, the parser reads beyond the end of the buffer. This can cause the application to crash. In some cases, bytes read past the buffer boundary may be incorporated into stream metadata, which could result in limited information disclosure.
- Vendor
- Red Hat
- Product
- Red Hat Enterprise Linux 10
- CVSS
- HIGH 7.1
- CISA KEV
- Not listed in stored evidence
- Original CVE published
- 2026-06-15
- Original CVE updated
- 2026-06-15
- Advisory published
- 2026-06-15
- Advisory updated
- 2026-06-15
Who should care
Users of GStreamer RealMedia demuxer (gst-plugins-ugly) should be aware of this vulnerability. Particularly, developers and maintainers of applications that utilize this demuxer for processing RealMedia files should take necessary actions to mitigate the risk.
Technical summary
The vulnerability is caused by the lack of proper bounds checking when parsing MDPR chunks in RealMedia files. Specifically, the parser does not verify if the chunk contains enough data before reading fields for audio stream header versions 4 and 5. This can lead to a buffer overflow, causing the application to crash or potentially disclose limited information.
Defensive priority
HIGH
Recommended defensive actions
- Update to the latest version of GStreamer RealMedia demuxer (gst-plugins-ugly) that includes the fix for this vulnerability.
- Avoid processing untrusted RealMedia files until the update is applied.
Evidence notes
The CVE-2026-53703 vulnerability has been documented in various sources, including the official CVE record [cve-org] and the National Vulnerability Database [nvd]. Additional information can be found in Red Hat's security advisory [ref-4] and bugzilla entry [ref-5].
Official resources
CVE-2026-53703 was published on 2026-06-15T20:16:33.563Z and modified on 2026-06-15T21:09:52.020Z.