Remote code execution via malformed PDB COMDAT data
Published Sep 8, 2026 · Updated Sep 9, 2026
Heap-based buffer overflow in Microsoft Visual Studio 2026 version 18.9 allows remote attackers to execute code via a crafted PDB file. Microsoft.DiaSymReader.Native mishandles malformed COFF COMDAT data while processing the PDB, causing a heap overwrite that redirects execution. Exploitation requires user interaction to process the attacker-supplied PDB, after which code executes in the Visual Studio user's context.
Summary
What happened
Heap-based buffer overflow in Microsoft Visual Studio 2026 version 18.9 allows remote attackers to execute code via a crafted PDB file. Microsoft.DiaSymReader.Native mishandles malformed COFF COMDAT data while processing the PDB, causing a heap overwrite that redirects execution. Exploitation requires user interaction to process the attacker-supplied PDB, after which code executes in the Visual Studio user's context.
The record
- CVE
- CVE-2026-77906
- Published
- Sep 8, 2026
- Updated
- Sep 9, 2026
- Vendor
- Microsoft
- Product
- Microsoft Visual Studio 2026 version 18.9
- Classifications
- CWE-122, T1204.002, T1203
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Sep 8, 2026CVE publishedPublication date reported by the CVE source.
- Sep 9, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=18.9.0 <18.9.3
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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