Improper Input Validation in TYPO3 Extension Affects User Record Editing
CVE-2026-77140

8.7HIGH

Key Information:

Vendor

Typo3

Status
Extension "telephone Directory"
Vendor
CVE Published:
25 August 2026

What is CVE-2026-77140?

The TYPO3 extension contains a flaw where the HMAC validation for editing employee records is only performed when rendering the edit form. This oversight leaves a significant security gap, allowing unauthenticated users who are aware of a valid employee UID to directly issue a POST request to the update action. Consequently, they can overwrite employee records without requiring a legitimate edit link or any ownership verification, posing a threat to sensitive data integrity.

Affected Version(s)

Extension "Telephone Directory" 0 < 6.2.0

References

https://typo3.org/security/advisory/typo3-ext-sa-2026-018
vendor-advisory

CVSS V4

Score:
8.7
Severity:
HIGH
Confidentiality:
None
Integrity:
High
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Seungbin Yang
Hoja Mustaffa Abdul Latheef
.