# CVE-2026-34212: Docmost stored XSS in attachment URLs

Source: https://junglewise.ai/threats/cve-2026-34212-docmost-stored-xss-in-attachment-urls  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-04-14. Updated: 2026-07-25  
License: CC BY 4.0 with a link back

CVE-2026-34212 · Severity: medium · CVSS 5.4 · Published 2026-04-14

Docmost is an open-source collaborative wiki and documentation platform. A security flaw allows users with basic editing permissions to embed malicious scripts within page attachments. If another user clicks on the affected attachment, the attacker's script will run in their browser, potentially allowing the attacker to steal session information or perform actions on the victim's behalf.

Technologies: [Docmost](https://junglewise.ai/threats/technologies/docmost). Vendors: [Docmost](https://junglewise.ai/threats/vendors/docmost).

## Quick answers

**Is CVE-2026-34212 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-34212 being exploited in the wild.

**How severe is CVE-2026-34212?** Medium severity, with a CVSS score of 5.4, published 14 April 2026.

**Which products and versions are affected?** Docmost < 0.71.0.

**Is there a fix for CVE-2026-34212?** A patch was published on 2026-04-14: Version 0.71.0 released Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-34212 attacked?** It is attacked over the network, in a web application.

**Am I affected by CVE-2026-34212?** Check whether you run Docmost at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

A stored cross-site scripting (XSS) vulnerability exists in Docmost due to improper neutralization of attachment URL schemes. While standard link nodes in the editor explicitly block 'javascript:' URIs, the attachment extension fails to apply the same sanitization logic. An authenticated attacker with page-editing privileges can submit a crafted JSON payload containing a malicious 'javascript:' URL within an attachment node. When a victim interacts with the attachment link or icon, the script executes within the context of the application's origin. This issue is fixed in version 0.71.0.

## Affected products

- Docmost Docmost < 0.71.0

## Timeline

- 2026-03-23: other: Vulnerability validated by researcher
- 2026-04-14: disclosed
- 2026-04-14: advisory
- 2026-04-14: patched: Version 0.71.0 released

## References

- [https://github.com/docmost/docmost/security/advisories/GHSA-cf68-cff9-hq4w](https://github.com/docmost/docmost/security/advisories/GHSA-cf68-cff9-hq4w)

## Related threats

- [Docmost ZIP bomb in page-import feature](https://junglewise.ai/threats/cve-2026-65827-docmost-is-open-source-collaborative-wiki-and-documentation)
- [Docmost privilege escalation in workspace invitation](https://junglewise.ai/threats/cve-2026-52853-docmost-is-open-source-collaborative-wiki-and-documentation)
- [Docmost access control bypass in transclusion API](https://junglewise.ai/threats/cve-2026-52850-docmost-is-open-source-collaborative-wiki-and-documentation)
- [Docmost authorization bypass in page export](https://junglewise.ai/threats/cve-2026-48073-docmost-is-open-source-collaborative-wiki-and-documentation)
- [Docmost path traversal in avatar and logo endpoint](https://junglewise.ai/threats/cve-2026-48072-docmost-is-open-source-collaborative-wiki-and-documentation)