Unknown
Multiple Products
arduino-esp32 is an Arduino core for the ESP32, ESP32-S2, ESP32-S3, ESP32-C3, ESP32-C6 and ESP32-H2 microcontrollers. Prior to 3.3.8, the WebServer mu...
2026-05-13
Description
arduino-esp32 is an Arduino core for the ESP32, ESP32-S2, ESP32-S3, ESP32-C3, ESP32-C6 and ESP32-H2 microcontrollers. Prior to 3.3.8, the WebServer multipart form parser in arduino-esp32 allocates a Variable Length Array (VLA) on the stack whose size is derived from an attacker-controlled HTTP header field (Content-Type: multipart/form-data; boundary=...) without enforcing any length limit. Sending a boundary string longer than ~8000 characters overflows the 8192-byte task stack of the loopTask, causing a crash and potential remote code execution. This vulnerability is fixed in 3.3.8.
AI Analyst Comment
Remediation
Update Unknown Multiple Products to the latest version. Monitor for exploitation attempts and review access logs.
---METADATA---
VENDOR: oxyno-zeta
PRODUCT: s3-proxy
AFFECTED_VERSIONS: Prior to 5.0.0
---END_METADATA---
Description Summary:
The oxyno-zeta s3-proxy contains an authentication bypass vulnerability due to inconsistent path interpretation, allowing unauthorized S3 operations.
Executive Summary:
An unauthenticated attacker can perform unauthorized read, write, or delete operations on protected S3 buckets by exploiting a path-based authentication bypass in s3-proxy.
Vulnerability Details
CVE-ID: CVE-2026-42882
Affected Software: oxyno-zeta s3-proxy
Affected Versions: Prior to 5.0.0
Vulnerability: This is an authentication bypass vulnerability caused by a mismatch between how the authentication middleware and the bucket handler resolve URL paths. An unauthenticated attacker can use path traversal or encoded characters to access restricted S3 namespaces.
Business Impact
This flaw allows for unauthorized data modification or exfiltration from S3 storage, directly threatening data integrity and confidentiality. Given the 9.4 CVSS score, this is a major security failure that could lead to the total exposure of sensitive object storage.
Remediation Plan
Immediate Action: Upgrade to s3-proxy version 5.0.0 or later.
Proactive Monitoring: Review S3 access logs for unexpected access requests or operations performed on sensitive buckets from unauthorized sources.
Compensating Controls: Implement bucket-level policies and IAM restrictions that limit the IP addresses or roles authorized to access the storage backend.
Exploitation Status
Public Exploit Available: false
Analyst Notes: As of May 11, 2026, there is no public information indicating active exploitation of this vulnerability. However, due to the nature of the flaw, the potential for exploitation is high.
Analyst Recommendation
Administrators should update s3-proxy immediately to version 5.0.0. Furthermore, ensure that the principle of least privilege is applied to all IAM entities interacting with the affected S3 buckets.