CVE-2026-28221

Published: Apr 29, 2026 Last Modified: Apr 30, 2026
ExploitDB:
Other exploit source:
Google Dorks:
MEDIUM 6,5
Source: [email protected]
Attack Vector: network
Attack Complexity: low
Privileges Required: none
User Interaction: none
Scope: unchanged
Confidentiality: none
Integrity: low
Availability: low

Description

AI Translation Available

Wazuh is a free and open source platform used for threat prevention, detection, and response. From version 4.8.0 to before version 4.14.4, a stack-based buffer overflow exists in print_hex_string() in wazuh-remoted. The bug is triggered when formatting attacker-controlled bytes using sprintf(dst_buf + 2*i, '%.2x', src_buf[i]) on platforms where char is treated as signed and the compiled code sign-extends bytes before the variadic call. For input bytes such as 0xFF, the formatting can emit 'ffffffff' (8 chars) instead of 'ff' (2 chars), causing an out-of-bounds write past a fixed 2049-byte stack buffer. The vulnerable path is reachable remotely prior to any agent authentication/registration logic via TCP/1514 when an oversized length prefix causes the “unexpected message (hex)” diagnostic path to run. Additionally, the same unauthenticated oversized-message diagnostic path logs an attacker-controlled hex dump to /var/ossec/logs/ossec.log for each trigger, allowing remote log amplification that can degrade monitoring fidelity and consume disk/I/O. This log amplification is reachable even without triggering the sign-extension overflow (e.g., using bytes < 0x80). This issue has been patched in version 4.14.4.

EPSS (Exploit Prediction Scoring System)

Trend Analysis

EPSS (Exploit Prediction Scoring System)

Prevede la probabilità di sfruttamento basata su intelligence sulle minacce e sulle caratteristiche della vulnerabilità.

EPSS Score
0,0006
Percentile
0,2th
Updated

EPSS Score Trend (Last 2 Days)

121

Stack-based Buffer Overflow

Draft
Abstraction: Variant Structure: Simple
Common Consequences
Security Scopes Affected:
Availability Integrity Confidentiality Access Control Other
Potential Impacts:
Modify Memory Dos: Crash, Exit, Or Restart Dos: Resource Consumption (Cpu) Dos: Resource Consumption (Memory) Execute Unauthorized Code Or Commands Bypass Protection Mechanism Other
Applicable Platforms
Languages: C, C++, Memory-Unsafe
Likelihood of Exploit: High
View CWE Details
400

Uncontrolled Resource Consumption

Draft
Abstraction: Class Structure: Simple
Common Consequences
Security Scopes Affected:
Availability Access Control Other
Potential Impacts:
Dos: Crash, Exit, Or Restart Dos: Resource Consumption (Cpu) Dos: Resource Consumption (Memory) Dos: Resource Consumption (Other) Bypass Protection Mechanism Other
Applicable Platforms
Technologies: AI/ML, Not Technology-Specific
Likelihood of Exploit: High
View CWE Details
Application

Wazuh by Wazuh

Product Information
Vendor Wazuh
Product Wazuh
Version Range Affected
From 4.8.0 (inclusive)
To 4.14.4 (exclusive)
cpe:2.3:a:wazuh:wazuh:*:*:*:*:*:*:*:*
Common Platform Enumeration - Standardized vulnerability identification
https://github.com/wazuh/wazuh/security/advisories/GHSA-q9v…
https://github.com/wazuh/wazuh/security/advisories/GHSA-q9vv-7w4c-f4cm
https://github.com/wazuh/wazuh/releases/tag/v4.14.4
https://github.com/wazuh/wazuh/releases/tag/v4.14.4
https://github.com/wazuh/wazuh/security/advisories/GHSA-q9v…
https://github.com/wazuh/wazuh/security/advisories/GHSA-q9vv-7w4c-f4cm