SB2026082753 - Authorization bypass through user-controlled key in Telephone Directory extension for TYPO3
Published: August 27, 2026
Security Bulletin ID
SB2026082753
CSH Severity
Medium
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Remote access
Highest impact
Data manipulation
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 vulnerability.
1) Authorization bypass through user-controlled key (CVE-ID: CVE-2026-77140)
CWE-ID: CWE-639 - Authorization Bypass Through User-Controlled Key
CVSSv4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to compromise the target system.
The vulnerability exists due to the affected extension validates the HMAC of a frontend employee edit link only in the action that renders the edit form, not in the action that persists the change. A remote attacker can overwrite the record without a valid edit link or any ownership check.
Remediation
Install update from vendor's website.