CVE-2026-23921

Blind, read-only SQL injection in Zabbix API via sortfield parameter

Published Mar 24, 2026 CVSS 4.0 · 8.7 High EPSS 4.2% KEV · Not listed
Description
A low privilege Zabbix user with API access can exploit a blind SQL injection vulnerability in include/classes/api/CApiService.php to execute arbitrary SQL selects via the sortfield parameter. Although query results are not returned directly, an attacker can exfiltrate arbitrary database data through time-based techniques, potentially leading to session identifier disclosure and administrator account compromise.

Analysis

AI-generated

Technical impact

A low‑privileged Zabbix user with API access can influence the sortfield parameter in the API to inject arbitrary, read‑only SQL statements. The injected SELECT commands do not return results directly, but an attacker can still extract database information by measuring timing responses or other side‑channels. This capability could lead to disclosure of session identifiers or even compromise of administrator accounts.

Affected Systems

The vulnerability exists in Zabbix’s API component located in include/classes/api/CApiService.php. Versions affected are not explicitly enumerated in the advisory, so any deployment exposing the Zabbix API to users with API rights may be susceptible.

Risk and Exploitability

With a CVSS base score of 8.7, this issue is rated as high risk. The EPSS score is 3%, and it is not listed in the CISA KEV catalog, though that is not a mitigation. An attacker only needs low‑privilege API access; the exploit requires normal network connectivity to the Zabbix server. Although direct data retrieval is not possible in the response, time‑based inference allows exfiltration, making the attack practical. The potential impact includes data confidentiality loss and possible administrative privilege escalation.

Remediation

Vendor Solution

Update the affected components to their respective fixed versions.


OpenCVE Recommended Actions

  • Apply the vendor patch that updates Zabbix API components to the fixed version.
  • Restrict API permissions so that only trusted users have access to the sortfield parameter.
  • Monitor API logs for unusual timing patterns or repeated queries that may indicate exploitation.

Generated by OpenCVE AI on August 24, 2026 at 16:22 UTC.

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
CPEs cpe:2.3:a:zabbix:zabbix:*:*:*:*:*:*:*:*
Metrics cvssV3_1

{'score': 8.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'}

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Zabbix
Zabbix zabbix
Vendors & Products Zabbix
Zabbix zabbix
Type Values Removed Values Added
Description A low privilege Zabbix user with API access can exploit a blind SQL injection vulnerability in include/classes/api/CApiService.php to execute arbitrary SQL selects via the sortfield parameter. Although query results are not returned directly, an attacker can exfiltrate arbitrary database data through time-based techniques, potentially leading to session identifier disclosure and administrator account compromise.
Title Blind, read-only SQL injection in Zabbix API via sortfield parameter
Weaknesses CWE-89
References
Metrics cvssV4_0

{'score': 8.7, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N'}

Weaknesses
  • CWE-89

    Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection')

Sources

Status
PUBLISHED
Assigner
Zabbix
Published
Updated
Mar 26, 2026, 3:55 AM
Reserved
Jan 19, 2026, 2:02 PM
Status
Analyzed
Published
Mar 24, 2026, 7:16 PM
Modified
Sep 10, 2026, 9:13 PM