CVE-2026-52722 Overview
CVE-2026-52722 is a signed integer overflow vulnerability in the GStreamer VMnc decoder. A crafted VMnc video stream with large cursor dimensions overflows signed integer arithmetic used to compute the payload size. The overflow bypasses a length check and triggers out-of-bounds reads in the decoder. A remote attacker can exploit the flaw by tricking a user into opening a malicious VMnc file, resulting in a crash or disclosure of process memory. The weakness is classified under [CWE-190] Integer Overflow or Wraparound.
Critical Impact
Remote attackers can crash GStreamer-based media applications or read out-of-bounds memory through a crafted VMnc file, enabling denial of service and potential information disclosure.
Affected Products
- GStreamer multimedia framework (VMnc decoder component)
- Linux distributions packaging vulnerable GStreamer versions (see Red Hat advisory)
- Applications embedding GStreamer for video playback or transcoding
Discovery Timeline
- 2026-06-15 - CVE-2026-52722 published to NVD
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2026-52722
Vulnerability Analysis
The GStreamer VMnc decoder parses VMware VMnc-encoded video streams, including embedded cursor update packets. Cursor packets carry width and height fields that the decoder multiplies together with a bytes-per-pixel value to compute the payload size. The resulting product is stored in a signed integer. Supplying large cursor dimensions causes the multiplication to overflow into a negative or truncated value.
The subsequent length check compares the overflowed size against the remaining buffer length. Because the overflow yields a value that appears valid, the check passes. The decoder then reads cursor pixel data using the attacker-controlled dimensions, accessing memory beyond the input buffer boundaries.
The out-of-bounds read can crash the host process or expose adjacent heap memory contents to the attacker through subsequent rendering or transcoding operations. User interaction is required: a victim must open or process the malicious VMnc file in a GStreamer-backed player or pipeline.
Root Cause
The root cause is unchecked signed integer arithmetic in the VMnc cursor handling path. The decoder trusts attacker-supplied width and height values without validating that their product fits within INT_MAX before performing the length comparison.
Attack Vector
Exploitation requires delivering a crafted VMnc file to a victim by email, web download, or shared storage. Opening the file in any application using the vulnerable GStreamer pipeline triggers the overflow. No authentication is required, but user interaction is necessary.
The vulnerability manifests in the VMnc cursor parsing routine where width * height * bytes_per_pixel is computed without overflow protection. See the GStreamer Work Item #5107 for upstream technical details.
Detection Methods for CVE-2026-52722
Indicators of Compromise
- Unexpected crashes in processes loading libgstvmnc or GStreamer media pipelines
- VMnc (.vmnc, .vmrec) files delivered from untrusted sources or email attachments
- Core dumps from gst-launch-1.0, totem, or other GStreamer-based players referencing the VMnc plugin
Detection Strategies
- Inspect inbound file transfers and email gateways for VMnc media files originating from untrusted senders
- Enable AddressSanitizer or equivalent runtime checks in test environments to catch out-of-bounds reads during media file processing
- Audit installed GStreamer plugin packages against fixed versions provided by the Red Hat CVE-2026-52722 Advisory
Monitoring Recommendations
- Forward application crash telemetry from desktop and server hosts to a central logging platform for correlation
- Alert on repeated segmentation faults in GStreamer worker processes across the fleet
- Monitor package management events for installation or downgrade of gstreamer-plugins-bad and related components
How to Mitigate CVE-2026-52722
Immediate Actions Required
- Apply distribution updates for GStreamer as soon as vendor patches become available through the Red Hat CVE-2026-52722 Advisory
- Block or quarantine VMnc files at email and web proxies until patched builds are deployed
- Restrict execution of media players on servers that do not require multimedia decoding
Patch Information
The upstream fix is tracked in GStreamer Work Item #5107. Distribution-specific package updates are coordinated through the Red Hat Bug Report #2486733. Administrators should consult their distribution's security advisories for fixed package versions and install updates through standard package management tooling.
Workarounds
- Disable or remove the VMnc decoder plugin from GStreamer installations where VMnc playback is not required
- Configure media applications to reject files with the VMnc container or .vmnc extension
- Run media processing in sandboxed environments such as Flatpak or containers to limit the blast radius of any successful exploitation
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
