Authenticated code execution via heap overflow
Published Aug 11, 2026 · Updated Aug 25, 2026
Heap-based buffer overflow in Microsoft Exchange Server before the August 11, 2026 updates allows remote authenticated users to execute code. Microsoft has not disclosed the vulnerable component, request path, or patch diff, so the specific Exchange routine that writes past a heap buffer remains undisclosed. Exploitation requires valid credentials and network reachability to an affected Exchange server; published records describe code execution but no public exploitation evidence.
Summary
What happened
Heap-based buffer overflow in Microsoft Exchange Server before the August 11, 2026 updates allows remote authenticated users to execute code. Microsoft has not disclosed the vulnerable component, request path, or patch diff, so the specific Exchange routine that writes past a heap buffer remains undisclosed. Exploitation requires valid credentials and network reachability to an affected Exchange server; published records describe code execution but no public exploitation evidence.
The record
- CVE
- CVE-2026-62913
- Published
- Aug 11, 2026
- Updated
- Aug 25, 2026
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-122, T1190
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Aug 11, 2026CVE publishedPublication date reported by the CVE source.
- Aug 25, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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What conditions does exploitation require?
What is affected?
Affected products and versions are unavailable in this record.
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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