Authenticated code execution via heap buffer overflow
Published Jul 14, 2026 · Updated Jul 14, 2026
Heap-based buffer overflow in Microsoft Exchange Server allows remote authenticated users to execute code over a network. Microsoft has not disclosed the affected Exchange component, the input that reaches it, or the memory operation that overruns a heap buffer. Low-privileged Exchange access is required; successful exploitation executes attacker-controlled code on the Exchange server.
Summary
What happened
Heap-based buffer overflow in Microsoft Exchange Server allows remote authenticated users to execute code over a network. Microsoft has not disclosed the affected Exchange component, the input that reaches it, or the memory operation that overruns a heap buffer. Low-privileged Exchange access is required; successful exploitation executes attacker-controlled code on the Exchange server.
The record
- CVE
- CVE-2026-55005
- Published
- Jul 14, 2026
- Updated
- Jul 14, 2026
- Vendor
- Microsoft
- Product
- Microsoft Exchange Server 2019 Cumulative Update 14
- Classifications
- CWE-122, T1190
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Jul 14, 2026CVE publishedPublication date reported by the CVE source.
- Jul 14, 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=15.02.0.0 <15.02.1544.043
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.
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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