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Medium · 5.4 Public exploit CVE-2026-34213 EUVD-2026-22756

Docmost has cross-page attachment overwrite via flawed attachmentId overwrite validation

Published Apr 14, 2026 · Updated Apr 15, 2026 · Assigned by GitHub_M

Vendor: docmost Product: docmost

Description

Docmost is open-source collaborative wiki and documentation software. Starting in version 0.3.0 and prior to version 0.71.0, improper authorization in Docmost allows a low-privileged authenticated user to overwrite another page's attachment within the same workspace by supplying a victim `attachmentId` to `POST /api/files/upload`. This is a remote integrity issue requiring no victim interaction. Version 0.71.0 contains a patch.

Affected products

VendorProductAffectedFixed
docmost docmost >= 0.3.0, < 0.71.0 —

Public exploits

Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.

Third-party code, not reviewed by us. Public PoCs are sometimes fake or contain malware. Read the code first and run it only in an isolated lab, against systems you are authorised to test.

GitHub 1 repository

  • 0xmrma/CVE-2026-34213 ★ 0 · Jun 26, 2026

    A low-privileged Docmost user could supply a victim attachmentId to the generic upload endpoint and overwrite another page's stored attachment inside the same workspace.

Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.

References