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...
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
- Severity
- CVSS 9.5 · Critical
- Confidence
- High
- Exploit status
- Exploited in the wild
- EPSS
- 0.6%
- First observed
- —
- Last observed
- —
Decision summary
What security teams need to know first
Direct answers before the deeper technical record.
Is it exploited?
Yes. Previdian tracks this CVE as a known exploited vulnerability. Confidence is high.
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.
Vendor
Product
Affected
Status
- 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
Independent exploitation attestation added to the Previdian record.
Known exploited vulnerability sources
Per-source evidence links for KEV attestations are available through the Previdian Pro API.
Learn about Pro API access| 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
- 0
- User-Agents
- 0
Raw values available in Pro and 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
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
0.6%
Timeline
From disclosure to observed exploitation
-
Added to the Previdian watchlist
Added to the Previdian curated list for closer monitoring
-
Added to Previdian KEV Feed
High-confidence, third-party attested exploitation
-
CVE published
Vulnerability disclosed publicly
-
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.
- 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": 0.00554,
"exploit_status": {
"exploited_in_the_wild": true,
"active_exploitation_observed": false
},
"sensor_telemetry": { "attempts": 0, "sensors": 0 }
}Early warning alerts
Get alerts on high-impact exploitation
Receive curator-selected alerts when exploitation activity warrants attention. Each alert includes the evidence and context needed to decide what requires attention now.