CVE-2026-6409

Updated on 16 Apr 2026

Severity

7.1 High severity

Details

CVSS score
7.1
CVSS vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Overview

About vulnerability

Impact

A Denial of Service (DoS) vulnerability exists in the Protobuf PHP library during the parsing of untrusted input. Maliciously structured messages—specifically those containing negative varints or deep recursion—can be used to crash the application, impacting service availability.

Patches

Patches have been released to 5.34.0-RC1 and 4.33.6.

Details

Affected product:
google/protobuf
Affected packages:
google/protobuf @ 3.24.4 (+1 more)

Fixes