Detection bypass via inherited SMTP MIME state
Published Sep 18, 2026 · Updated Sep 18, 2026
Improper initialization in Suricata's SMTP MIME parser in versions 8.0.0 through 8.0.5 allows remote attackers to bypass detections. When message/rfc822 encapsulation begins, rust/src/mime/smtp.rs fails to clear the outer MIME part's encoding or filename state, so the inner message inherits it. Exploitation requires SMTP MIME decoding; affected rules can miss file.data, file.name, or extracted-URL indicators without crashing the engine.
Summary
What happened
Improper initialization in Suricata's SMTP MIME parser in versions 8.0.0 through 8.0.5 allows remote attackers to bypass detections. When message/rfc822 encapsulation begins, rust/src/mime/smtp.rs fails to clear the outer MIME part's encoding or filename state, so the inner message inherits it. Exploitation requires SMTP MIME decoding; affected rules can miss file.data, file.name, or extracted-URL indicators without crashing the engine.
The record
- CVE
- CVE-2026-57229
- Published
- Sep 18, 2026
- Updated
- Sep 18, 2026
- Vendor
- Open Information Security Foundation
- Product
- Suricata
- Classifications
- CWE-665, T1027.013
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Sep 18, 2026CVE publishedPublication date reported by the CVE source.
- Sep 18, 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=>= 8.0.0, < 8.0.6
What conditions does exploitation require?
What is affected?
Published CVSS scores
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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
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Technologies
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