Vulnerability report

Exploited in the wild High confidence Not in CISA KEV

CVE-2026-77136

Server-Side Template Injection in extension "powermail" (powermail)

TYPO3 / Extension "powermail" · affected before 13.2.1

Watch CVE-2026-77136 Browse KEV feed
Severity
CVSS 9.5 · Critical
Confidence
High
Exploit status
Exploited in the wild
EPSS
1.0%
First observed
—
Last observed
—

Decision summary

What security teams need to know first

Direct answers before the deeper technical record.

What it is

CVE-2026-77136 is an unauthenticated Server-Side Template Injection in extension "powermail" (powermail) affecting TYPO3 Extension "powermail". The extension passes the raw value of a form field configured as "This...

Is it exploited?

Yes. Previdian tracks this CVE as a known exploited vulnerability. Confidence is high. Also confirmed by third-party sources.

Who is affected?

TYPO3 / Extension "powermail" affected before 13.2.1.

What should we do?

Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.

Overview

Server-Side Template Injection in extension "powermail" (powermail)

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.

TYPO3 Affected
Extension "powermail" in2code/powermail
Before 13.2.1 Before 12.6.1 Before 10.9.3
View vendor advisory (opens in new tab)
Published
25 Aug 2026
Exploitation Reported
25 Aug 2026
Attack vector
Remote
Complexity
Low
Privileges
None
User interaction
None

CVE References

  • CVE Record CVE.org · CVE Record https://www.cve.org/CVERecord?id=CVE-2026-77136
  • Vendor Advisory — typo3.org typo3.org · Vendor Advisory https://typo3.org/security/advisory/typo3-ext-sa-2026-022

Exploitation evidence

Why Previdian marks this CVE as exploited

Third-party attestation and first-party sensor observation are shown separately so teams can judge the evidence chain.

Exploited in the wild

CVE

Recorded 25 Aug 2026

A trusted third party reported exploitation.

Known exploited vulnerability sources

Per-source evidence links for KEV attestations are available through the Previdian Pro API.

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Source Added
CVE First 2026-08-25 09:10 UTC

Detection

Operational artifacts and observed signals

Make the evidence actionable in scanner, SOC, and edge-control workflows.

Observed signals

Request targets
User-Agents
Callback hosts
0
0
0

Request targets and User-Agents available in Pro. Callback host details available in Enterprise.

Scanner coverage

No scanner integrations recorded yet.

Virtual patch status

No Previdian virtual patch is currently available. Future rules ship for ModSecurity, Cloudflare, and AWS WAF.

Learn about virtual patches →

No detection artifacts or sensor request patterns are available for this CVE yet.

Check back as sensor telemetry and scanner integrations are updated.

Risk and context

Severity, weaknesses, and research context

CVSS v4.0

9.5 Critical

Potential damage if exploited. Separate from whether attackers are using it.

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

EPSS

1.0%

Estimated chance of exploitation in the next 30 days. Previdian's warning comes from evidence, not this score.

Weaknesses

Improper Neutralization of Special Elements Used in a Template Engine CWE-1336

Timeline

From disclosure to observed exploitation

  1. 09:20 UTC

    Added to the Previdian watchlist

    Added to the Previdian curated list for closer monitoring

  2. 09:10 UTC

    Added to Previdian KEV Feed

    High-confidence, third-party attested exploitation

  3. 09:00 UTC

    CVE published

    Vulnerability disclosed publicly

  4. 13:10 UTC

    CVE ID reserved

    Identifier reserved by the CNA

Pro API

Automate this intelligence

Confidence, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.

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  • Evidence confidence and provenance
  • First-party sensor telemetry
  • PoC and scanner references
  • Affected versions and enrichment
  • Automation-ready JSON delivery

GET /api/v2/pro/kevs/CVE-2026-77136

Free JSON includes basic KEV fields 
{
  "cve_id": "CVE-2026-77136",
  "confidence": "High",
  "cvss_score": 9.5,
  "cvss_estimated": false,
  "epss_score": 0.00968,
  "exploit_status": {
    "exploited_in_the_wild": true,
    "active_exploitation_observed": false
  },
  "sensor_telemetry": { "attempts": 0, "sensors": 0 }
}