# CVE-2026-23921: Blind, read-only SQL injection in Zabbix API via sortfield parameter

> A low-privilege user can exploit blind SQL injection in the Zabbix API to exfiltrate database data and potentially compromise administrator accounts.

- **Severity:** High 8.7 (`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`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 24 Mar 2026
- **Updated:** 26 Mar 2026
- **Also known as:** DEBIAN-CVE-2026-23921, GHSA-j24v-fg24-6mqq, UBUNTU-CVE-2026-23921

## What is CVE-2026-23921?

CVE-2026-23921 is a high-severity SQL injection vulnerability in Zabbix Zabbix, published on 24 Mar 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official 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.

Weakness: CWE-89 (Improper Neutralization of Special Elements used in an SQL Command)

## Which versions are affected by CVE-2026-23921?

It affects 1 product.


Products: Zabbix Zabbix.

## How do I fix CVE-2026-23921?

Apply the vendor's patch.

## Is CVE-2026-23921 being exploited?

There is no known exploitation of CVE-2026-23921 in the wild and no public exploit code.

Public exploit code:

- This repository contains a proof-of-concept (PoC) exploit for CVE-2026-23921 (github_poc): https://github.com/qucklecrabik/CVE-2026-23921
- Caderno Temático NotebookLM: análise de vulnerabilidades SQL Injection (CVE-2024-42327, CVE-2026-23921) no Zabbix, com engenharia de prompts, cadeia de ataque até RCE e miniguia de hardening (github_poc): https://github.com/RichJJ98/analise-vulnerabilidades-zabbix-notebooklm

## Other vulnerabilities in Zabbix Zabbix

- [CVE-2022-23131](https://insights.sbomify.com/CVE-2022-23131/): Zabbix Frontend Authentication Bypass (critical 9.1, exploited in the wild)
- [CVE-2007-0640](https://insights.sbomify.com/CVE-2007-0640/): Memory corruption in n/a (critical 10.0)
- [CVE-2024-42327](https://insights.sbomify.com/CVE-2024-42327/): SQL injection in user.get API (critical 9.9)
- [CVE-2024-22116](https://insights.sbomify.com/CVE-2024-22116/): Remote code execution within ping script (critical 9.9)
- [CVE-2013-3738](https://insights.sbomify.com/CVE-2013-3738/): Code injection in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-23921 and fix it if it is affected.

What it is: CVE-2026-23921 is a high-severity SQL injection vulnerability in Zabbix Zabbix, published on 24 Mar 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-23921 in the wild and no public exploit code.

Affected product: Zabbix Zabbix. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-23921/ (Markdown: https://insights.sbomify.com/CVE-2026-23921/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-23921
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-23921
- OSV: https://osv.dev/vulnerability/CVE-2026-23921

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-23921/
Summaries are generated and may contain mistakes; the official description above is the record.