CVE-2026-77139Network attack vector

Authenticated HTML file write or deletion via traversal

Published Aug 25, 2026 · Updated Aug 25, 2026

Path traversal in TYPO3 Mask 8.3.11 and earlier and 9.0.0 through 9.0.10 allows remote authenticated users to create or delete HTML files. Mask uses a client-supplied template element key to construct save and delete paths without rejecting traversal sequences, allowing .html paths to escape the configured template directory. Access to the authenticated TYPO3 backend and permission to use the Mask module are required; the bounded result is creation or deletion of .html files writable by the web process.

CVSS severity6.0
Medium
EPSS probability0.29%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Path traversal in TYPO3 Mask 8.3.11 and earlier and 9.0.0 through 9.0.10 allows remote authenticated users to create or delete HTML files. Mask uses a client-supplied template element key to construct save and delete paths without rejecting traversal sequences, allowing .html paths to escape the configured template directory. Access to the authenticated TYPO3 backend and permission to use the Mask module are required; the bounded result is creation or deletion of .html files writable by the web process.

The record

CVE
CVE-2026-77139
Published
Aug 25, 2026
Updated
Aug 25, 2026
Vendor
in2code GmbH
Product
Mask
Classifications
CWE-73, CWE-22, T1565.001
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 25, 2026CVE publishedPublication date reported by the CVE source.
  2. 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.

  1. Affected versionversion=0 <8.3.12
  2. Affected versionversion=9.0.0 <9.0.11

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

in2code GmbH · Maskversion=0 <8.3.12; version=9.0.0 <9.0.11

Published CVSS scores

6.0TYPO3CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-73External Control of File Name or Path
CWE-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
T1565.001Stored Data Manipulation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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