GStreamer ASF Demuxer Heap-based Buffer Overflow Remote Code Execution Vulnerability. This vulnerability allows remote attackers to execute arbitrary code on affected installations of GStreamer. Interaction with this library is required to exploit this vulnerability but attack vectors may vary depending on the implementation.
The specific flaw exists within the processing of stream headers within ASF files. The issue results from the lack of proper validation of the length of user-supplied data prior to copying it to a fixed-length heap-based buffer. An attacker can leverage this vulnerability to execute code in the context of the current process. Was ZDI-CAN-28843.
Security readout for executives and security teams
Plain-English summary
CVE-2026-2920 is a high-severity memory corruption flaw in GStreamer's ASF demuxer. A crafted ASF media file can trigger a heap buffer overflow while stream headers are processed, potentially letting an attacker run code inside the application using GStreamer.
Executive priority
Treat as a near-term patching priority for media-processing, desktop, and upload-handling environments. Prioritize internet-facing or user-submitted media workflows first. No active exploitation is evidenced in the provided bundle.
Technical view
The flaw is missing length validation before copying user-controlled ASF stream-header data into a fixed-size heap buffer. ZDI describes potential arbitrary code execution in the current process. The supplied CVSS is 7.8 with user interaction required and high confidentiality, integrity, and availability impact.
Likely exposure
Exposure is most likely where GStreamer parses ASF media from users, downloads, email attachments, web uploads, transcoding queues, or media preview workflows. The supplied affected version data is incomplete and lists a commit-like identifier with unknown default status, so organizations should verify package-specific advisories.
Exploitation context
The bundle does not show CISA KEV listing or confirmed active exploitation. ZDI says remote attackers can exploit affected installations, but interaction with the library is required and attack vectors vary by implementation.
Researcher notes
Track ZDI-CAN-28843 and the upstream GStreamer commit. Key uncertainty is affected version mapping beyond the supplied commit-like identifier. Avoid assuming all GStreamer deployments are exploitable without confirming ASF demuxer presence and package backport status.
Mitigation direction
Apply upstream or distribution updates that include the GStreamer ASF demuxer fix.
For Red Hat systems, review the listed RHSA advisories and update affected packages.
Limit or disable ASF parsing from untrusted sources where patching is delayed.
Route uploaded media through quarantine and controlled scanning workflows.
Monitor GStreamer and vendor advisories for corrected version mapping.
Validation and detection
Inventory systems and applications using GStreamer ASF demuxing.
Check installed package status against upstream commit 37d7991168a223d0810fd1f4493ec6a8b6a510d3.
Review Red Hat CSAF, CVE, Bugzilla, and RHSA entries for affected package decisions.
Confirm media ingestion paths cannot automatically process untrusted ASF files unpatched.
Verify patched builds include proper stream-header length validation.
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Potential ATT&CK relevance
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
cwe · low confidence lookup
CWE-120: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
2CVSS vectors
5Timeline events
2ADP providers
13Source links
SSVC decision data
CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: noneAutomatable: noTechnical Impact: total
CVSS vector scores
2 official scores
We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
CWE-120 · source CWE mapping
Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
Buffer Copy without Checking Size of Input ('Classic Buffer Overflow') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.
Heap-based Buffer Overflow represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.