# CVE-2026-53704: GStreamer RealMedia demuxer out-of-bounds read in FILEINFO metadata

Source: https://junglewise.ai/threats/cve-2026-53704-gstreamer-realmedia-demuxer-out-of-bounds-read-in-fileinfo  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-06-15. Updated: 2026-06-15  
License: CC BY 4.0 with a link back

CVE-2026-53704 · Severity: high · CVSS 7.1 · Published 2026-06-15

A vulnerability exists in GStreamer, a widely used multimedia framework for handling audio and video content. By tricking a user into opening a specially crafted RealMedia file, an attacker can cause the media player to crash or hang indefinitely, leading to a denial of service. In some cases, this flaw could also allow the unauthorized reading of small amounts of memory, potentially exposing sensitive information.

Technologies: [Gstreamer Gst-Plugins-Ugly](https://junglewise.ai/threats/technologies/gst-plugins-ugly). Vendors: [Gstreamer](https://junglewise.ai/threats/vendors/gstreamer).

## Quick answers

**Is CVE-2026-53704 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-53704 being exploited in the wild.

**How severe is CVE-2026-53704?** High severity, with a CVSS score of 7.1, published 15 June 2026.

**Which products and versions are affected?** Gstreamer Gst-Plugins-Ugly unspecified.

**Is there a fix for CVE-2026-53704?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-53704 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-53704?** Check whether you run Gstreamer Gst-Plugins-Ugly or Gstreamer Gst-Plugins-Ugly-Free at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

An out-of-bounds read and infinite loop vulnerability exists in the GStreamer RealMedia demuxer (gst-plugins-ugly) within the gst_rmdemux_parse_mdpr() function. The issue stems from the FILEINFO metadata parser using re_skip_pascal_string() to advance offsets without performing bounds checking against the mapped buffer. Furthermore, the 'element_nb' loop controller is an attacker-controlled signed integer; providing a value such as 0xFFFFFFFF can trigger an infinite loop. An attacker can exploit this by providing a malformed RealMedia file, leading to a denial of service (crash or hang) or information disclosure via out-of-bounds memory reads. As of the advisory date, no official patch is available, and upstream developers recommend a rewrite of the rmdemux component.

## Affected products

- GStreamer gstreamer1-plugins-ugly-free unspecified
- GStreamer gst-plugins-ugly unspecified

## Timeline

- 2026-06-10: disclosed: Reported via PSIRTSUPT-7239 by Tianshuo Han
- 2026-06-15: advisory: NVD and Red Hat published advisory details

## References

- [https://access.redhat.com/security/cve/CVE-2026-53704](https://access.redhat.com/security/cve/CVE-2026-53704)
- [https://bugzilla.redhat.com/show_bug.cgi?id=2487614](https://bugzilla.redhat.com/show_bug.cgi?id=2487614)

## Related threats

- [GStreamer gst-plugins-ugly ASF demuxer unbounded memory allocation](https://junglewise.ai/threats/cve-2026-112214-a-flaw-was-found-in-the-gstreamer-asf-demuxer-in-gst-plugins)
- [GStreamer RealMedia demuxer out-of-bounds read in MDPR chunk parsing](https://junglewise.ai/threats/cve-2026-53703-gstreamer-realmedia-demuxer-out-of-bounds-read-in-mdpr-chunk)
- [GStreamer RealMedia Demuxer out-of-bounds write](https://junglewise.ai/threats/cve-2026-2922-gstreamer-realmedia-demuxer-out-of-bounds-write)