Internal service probing via unchecked link requests
Published Feb 25, 2026 · Updated Feb 25, 2026
SSRF in Mailpit before 1.29.2 allows remote attackers to probe internal HTTP services through the Link Check API. The doHead function passes every URL extracted from a stored email to a plain HTTP client, makes HEAD requests without destination-IP validation, and returns each status code and text. Default deployments expose the SMTP and API paths without authentication, enabling internal host and port enumeration but not response-body retrieval.
Summary
What happened
SSRF in Mailpit before 1.29.2 allows remote attackers to probe internal HTTP services through the Link Check API. The doHead function passes every URL extracted from a stored email to a plain HTTP client, makes HEAD requests without destination-IP validation, and returns each status code and text. Default deployments expose the SMTP and API paths without authentication, enabling internal host and port enumeration but not response-body retrieval.
The record
- CVE
- CVE-2026-27808
- Published
- Feb 25, 2026
- Updated
- Feb 25, 2026
- Vendor
- Axllent
- Product
- Mailpit
- Classifications
- CWE-918, T1190, T1046
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Feb 25, 2026CVE publishedPublication date reported by the CVE source.
- Feb 25, 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=< 1.29.2
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
- Upstream Link Check SSRF proof of conceptproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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