CVE-2026-60103: Blender Buffer Overflow Vulnerability

CVE-2026-60103 Overview

CVE-2026-60103 is an out-of-bounds read vulnerability in Blender versions 3.0.0 through 5.1.2. The flaw resides in the sdna_expand_names() function, which processes the Structure DNA (SDNA) block of .blend files. Attackers can exploit the issue by supplying a crafted .blend file containing a malicious signed short member_index value. Because the field is used as an array index into sdna->members[] without bounds validation, values outside the allocated range produce an invalid pointer. That pointer is subsequently passed to strlen(), triggering a SIGSEGV crash or unintended heap memory disclosure. The vulnerability is tracked under [CWE-125] (Out-of-Bounds Read).

Critical Impact
A crafted .blend file can crash Blender or leak adjacent heap memory contents when opened by an unsuspecting user.

Affected Products

Blender 3.0.0 through 5.1.2
Blender file loader (sdna_expand_names() in SDNA parsing)
All platforms supporting affected Blender releases

Discovery Timeline

2026-07-13 - CVE-2026-60103 published to NVD
2026-07-15 - Last updated in NVD database

Technical Details for CVE-2026-60103

Vulnerability Analysis

Blender uses a Structure DNA (SDNA) block within .blend files to describe the layout of serialized data structures. During file load, sdna_expand_names() iterates over member entries and uses each member_index value as an index into the sdna->members[] array. The function accepts the value as a signed short without validating that it falls within the allocated array range.

When an attacker provides a member_index outside the valid bounds, the resulting pointer read from sdna->members[] references memory that Blender does not own or has not initialized for that purpose. The unchecked pointer is then handed to strlen(), which walks memory until it encounters a null byte. Depending on the surrounding heap layout, this either terminates the process with SIGSEGV or exposes the length and contents of adjacent heap allocations. Exploitation requires user interaction: the victim must open the crafted .blend file locally.

Root Cause

The root cause is missing bounds validation on the signed short member_index field parsed from untrusted file content. The SDNA parser trusts the value implicitly and dereferences the resulting pointer through strlen() without confirming that the index lies within sdna->members[]. This is a classic [CWE-125] out-of-bounds read pattern where attacker-controlled input drives array indexing.

Attack Vector

Exploitation requires local access and user interaction. An attacker distributes a malicious .blend file through channels such as asset marketplaces, shared project repositories, email attachments, or chat platforms. When a user opens the file in Blender, the SDNA parser processes the malicious member_index field, producing either a crash (denial of service) or a limited heap memory read. The vulnerability does not directly yield code execution, but heap disclosure can support secondary attacks by leaking pointers or sensitive data that defeat address space layout randomization.

See the VulnCheck Advisory on Blender for additional technical detail on the vulnerable code path.

Detection Methods for CVE-2026-60103

Indicators of Compromise

Unexpected Blender process crashes (SIGSEGV) shortly after opening a .blend file from an untrusted source.
.blend files sourced from unverified marketplaces, forums, or third-party downloads.
Core dumps referencing sdna_expand_names or strlen on the call stack during file load.

Detection Strategies

Inspect .blend files with a parser that validates SDNA member_index values against the declared sdna->members[] array length before processing.
Enable and collect application crash telemetry from workstations running Blender to identify repeated faults during file open.
Hunt for downloads of .blend files from newly registered domains or non-corporate storage locations in web proxy and email gateway logs.

Monitoring Recommendations

Alert on Blender processes that terminate abnormally during file I/O on artist and content-creation workstations.
Track Blender version inventory across managed endpoints to identify hosts still running 3.0.0 through 5.1.2.
Correlate file-open events with subsequent process crashes to surface potential exploitation attempts.

How to Mitigate CVE-2026-60103

Immediate Actions Required

Upgrade Blender to a version that includes the fix from the upstream patch referenced in the Blender Commit Update.
Instruct users to avoid opening .blend files from untrusted sources until patched builds are deployed.
Inventory all endpoints running Blender 3.0.0 through 5.1.2 and prioritize patching for workstations that regularly process third-party assets.

Patch Information

The upstream fix is available in the Blender repository. Refer to the Blender Commit Update and the corresponding Blender Pull Request for the code change that adds bounds validation on member_index before it is used to index sdna->members[].

Workarounds

Restrict Blender to opening .blend files from vetted internal repositories only.
Sandbox Blender execution using OS-level isolation (for example, Firejail on Linux or AppContainer on Windows) to limit the impact of heap disclosure.
Use a preprocessing step to validate SDNA structure integrity in .blend files received from external parties before opening them in Blender.

bash

# Configuration example: identify Blender installations requiring update
# Linux/macOS
blender --version

# Windows PowerShell inventory across managed hosts
Get-ChildItem -Path 'C:\Program Files\Blender Foundation' -Recurse -Filter 'blender.exe' |
  ForEach-Object { & $_.FullName --version }