CVE-2026-59691
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 · uneditedA heap buffer overflow vulnerability was found in GStreamer's rfbsrc plugin. When a client connects to a malicious RFB/VNC server that advertises a 16bpp framebuffer and sends Hextile-encoded updates, the Hextile background fill path writes 32-bit pixel values into a buffer allocated for 16-bit pixels. This type mismatch causes an out-of-bounds heap write that can lead to denial of service (process crash) and potential memory corruption.
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 · high confidenceHeap buffer overflow in GStreamer's rfbsrc plugin where the Hextile decoder writes 32-bit pixel values into a buffer allocated for 16-bit pixels when a 16bpp framebuffer is advertised, causing out-of-bounds heap write during background fill operations.
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
- None
- Integrity
- Low
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/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 checksWork through these to decide whether this CVE applies to you.
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Verify GStreamer installationRun `gst-inspect-1.0 --version` or check package manager for gstreamer packageAffected if GStreamer is not installed
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Confirm rfbsrc plugin presenceRun `gst-inspect-1.0 rfbsrc` to see if the plugin is availableAffected if rfbsrc plugin is installed and available
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Check GStreamer version against known fixCompare your installed GStreamer version to the version that contains the patch for this heap overflowAffected if Installed version is older than the patched version
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Identify active VNC pipelines using rfbsrcSearch configuration files, scripts, and running processes for gst-launch pipelines or applications using rfbsrc with VNC sourcesAffected if rfbsrc is actively used to connect to VNC servers
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Review Hextile encoding usageCheck if the VNC client configurations allow or default to Hextile encoding when connectingAffected if Hextile encoding is enabled or negotiated with VNC servers
You are affected if you use GStreamer with the rfbsrc plugin to connect to VNC servers and process Hextile-encoded 16bpp framebuffer updates from untrusted sources.
Generated from the published advisory. Verify against your own configuration.
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 dataAvoid connecting to untrusted VNC/RFB servers; apply vendor patches when available; the fix requires correcting the buffer allocation or pixel write size to match the framebuffer bit depth.
- Consultation3.0 h
- Implementation4.0 h
- Testing6.0 h
- Review / QA3.0 h
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 locallyCheck whether your project pulls in CVE-2026-59691 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-59691 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- 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
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