Memory disclosure via undisclosed out-of-bounds read
Published May 12, 2026 · Updated May 12, 2026
Out-of-bounds read in the Microsoft Telnet Client on affected Windows releases allows remote attackers to disclose memory over a network. Microsoft identifies the flaw as an out-of-bounds read but has not published the parsing locus or malformed Telnet input that triggers it. Exploitation requires a user to run the optional client and connect to an attacker-controlled Telnet endpoint; the record reports memory disclosure and no data modification.
Summary
What happened
Out-of-bounds read in the Microsoft Telnet Client on affected Windows releases allows remote attackers to disclose memory over a network. Microsoft identifies the flaw as an out-of-bounds read but has not published the parsing locus or malformed Telnet input that triggers it. Exploitation requires a user to run the optional client and connect to an attacker-controlled Telnet endpoint; the record reports memory disclosure and no data modification.
The record
- CVE
- CVE-2026-35423
- Published
- May 12, 2026
- Updated
- May 12, 2026
- Vendor
- Microsoft
- Product
- Windows Server 2019
- Classifications
- CWE-125
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- May 12, 2026CVE publishedPublication date reported by the CVE source.
- May 12, 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=10.0.17763.0 <10.0.17763.8755
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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