Server impersonation via certificate Common Name fallback
Published Oct 2, 2026 · Updated Oct 2, 2026
Certificate validation in Apache Thrift C++ and D clients through 0.24.0 allows man-in-the-middle attackers to impersonate a server. The default client access managers treat nonmatching dNSName subjectAltName entries as skips and then accept a matching certificate Common Name. Exploitation requires a network-path position and a certificate trusted by the client whose Common Name matches the connected host; deployments using private certificate authorities are particularly exposed.
Summary
What happened
Certificate validation in Apache Thrift C++ and D clients through 0.24.0 allows man-in-the-middle attackers to impersonate a server. The default client access managers treat nonmatching dNSName subjectAltName entries as skips and then accept a matching certificate Common Name. Exploitation requires a network-path position and a certificate trusted by the client whose Common Name matches the connected host; deployments using private certificate authorities are particularly exposed.
The record
- CVE
- CVE-2026-85088
- Published
- Oct 2, 2026
- Updated
- Oct 2, 2026
- Vendor
- The Apache Software Foundation
- Product
- Apache Thrift
- Classifications
- T1557
- Attack vector
- adjacent
- Privileges
- unauthenticated
Timeline
How it unfolded
- Oct 2, 2026CVE publishedPublication date reported by the CVE source.
- Oct 2, 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?
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- Affected versionversion=0 <0.25.0
What conditions does exploitation require?
What is affected?
Published CVSS scores
No CVSS assessment is available in this record.
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Attacks
What attackers are doing with it
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Activity data is delayed. The latest report is Sep 28, 2026.
Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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