Unauthenticated ViewHelper execution via sender-name template parsing
Published Aug 25, 2026 · Updated Aug 25, 2026
Server-side template injection in TYPO3 powermail allows remote attackers to execute Fluid ViewHelpers through public form submissions. SendMailService::parseAndOverwriteVariables passes visitor-controlled sender-name content to TemplateUtility::fluidParseString as a Fluid template source instead of limiting parsing to editor-configured keys. A form needs a field marked as the sender name; no account or user interaction is required, and execution can disclose configuration, environment variables, and source code or achieve remote code execution.
Summary
What happened
Server-side template injection in TYPO3 powermail allows remote attackers to execute Fluid ViewHelpers through public form submissions. SendMailService::parseAndOverwriteVariables passes visitor-controlled sender-name content to TemplateUtility::fluidParseString as a Fluid template source instead of limiting parsing to editor-configured keys. A form needs a field marked as the sender name; no account or user interaction is required, and execution can disclose configuration, environment variables, and source code or achieve remote code execution.
The record
- CVE
- CVE-2026-77136
- Published
- Aug 25, 2026
- Updated
- Aug 25, 2026
- Vendor
- in2code GmbH
- Product
- powermail
- Classifications
- CWE-1336, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 25, 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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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <10.9.3
- Affected versionversion=11.0.0 <12.6.1
- Affected versionversion=13.0.0 <13.2.1
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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Reported exploitation
- Vendor-reported active exploitation of powermail SSTIreported exploitation
Technologies
Your stack
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Your stack
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