# CVE-2026-23935: Use-after-free read in script item/preprocessing HttpRequest body

> A Zabbix administrator can read out-of-bounds memory via a use-after-free flaw in JavaScript HttpRequest logic, leading to potential confidentiality loss.

- **Severity:** Medium 6.8 (`CVSS:4.0/AV:A/AC:L/AT:N/PR:H/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 18 Aug 2026
- **Updated:** 18 Aug 2026
- **Also known as:** DEBIAN-CVE-2026-23935, GHSA-37pv-569q-qx93, UBUNTU-CVE-2026-23935

## What is CVE-2026-23935?

CVE-2026-23935 is a medium-severity use after free vulnerability in Zabbix Zabbix, published on 18 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

A Zabbix administrator is able to read out of bounds memory by utilizing a flaw in script item/preprocessing (JavaScript) HttpRequest logic, leading to potential confidentiality loss.

Weakness: CWE-125 (Out-of-bounds Read)

## Which versions are affected by CVE-2026-23935?

It affects 1 product.


Products: Zabbix Zabbix.

## How do I fix CVE-2026-23935?

Apply the vendor's patch.

## Is CVE-2026-23935 being exploited?

There is no known exploitation of CVE-2026-23935 in the wild and no public exploit code.

## 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-2026-23935 and fix it if it is affected.

What it is: CVE-2026-23935 is a medium-severity use after free vulnerability in Zabbix Zabbix, published on 18 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-23935 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-2026-23935/ (Markdown: https://insights.sbomify.com/CVE-2026-23935/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-23935
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-23935
- OSV: https://osv.dev/vulnerability/CVE-2026-23935

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-23935/
Summaries are generated and may contain mistakes; the official description above is the record.