dbcve.org
Heap-based Buffer OverflowWeakness · CWE-122

CVE-2026-52720

HIGH · 8.8 CVSS v3.1 Published 2026-06-15
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
95/100
Remediation priority · Urgent
Remotely reachable No privileges

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
A heap buffer overflow vulnerability was found in GStreamer's librfb (RFB/VNC client). The rectangle bounds check incorrectly validates area rather than individual dimensions, allowing a malicious VNC server to send a rectangle that extends beyond the framebuffer. A remote attacker could set up a malicious VNC server and trick a user into connecting, resulting in an out-of-bounds heap write that could lead to code execution or a crash.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

Heap buffer overflow in GStreamer's librfb where rectangle bounds checking incorrectly validates total area instead of individual width/height dimensions. A malicious VNC server can send a rectangle with dimensions exceeding framebuffer boundaries, causing out-of-bounds heap writes leading to potential code execution or crash.

MitigationUpdate GStreamer librfb to version with corrected rectangle bounds validation that checks individual dimensions before allocation/writing. Users should avoid connecting to untrusted VNC servers until patched.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify GStreamer installation and version
    Run 'gst-inspect-1.0 --version' or check package manager for gstreamer version (e.g., 'dpkg -l | grep gstreamer' on Debian/Ubuntu, 'rpm -qa | grep gstreamer' on RHEL/CentOS)
    Affected if GStreamer version is present and falls within the affected version range (if known) or is unpatched
  2. Confirm librfb component presence
    Run 'gst-inspect-1.0 rfb' or 'gst-inspect-1.0 librfb' to verify the rfb plugin is available
    Affected if The rfb/librfb element is listed and loadable by GStreamer
  3. Detect active VNC client usage
    Inspect running processes or application configurations for GStreamer pipelines using rfb elements (e.g., 'ps aux | grep -i vnc' or review application logs for 'rfb' or 'vnc' in GStreamer element names)
    Affected if Any application or service uses GStreamer with rfb/vnc client elements to connect to VNC servers
  4. Review heap memory behavior (optional runtime check)
    If feasible, monitor application memory allocation patterns when connecting to VNC servers using tools like 'valgrind' or memory debuggers to observe potential overflow conditions
    Affected if Unexpected memory writes or buffer overruns are observed during VNC session establishment

The environment is affected if GStreamer with librfb/rfb component is installed and actively used to connect to VNC servers, and the version is unpatched or within the affected range.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Update GStreamer librfb to version with corrected rectangle bounds validation that checks individual dimensions before allocation/writing. Users should avoid connecting to untrusted VNC servers until patched.

Have this fixed Scoped from the published advisory
  • Consultation3.0 h
  • Implementation4.0 h
  • Testing6.0 h
  • Review / QA3.0 h
16.0 hours of engineering $2,760
Get help mitigating

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,416.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2026-52720 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-52720 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data