CVE-2026-52853

Docmost, an open-source collaborative wiki and documentation software, versions 0.21.0 through before 0.24.0, is vulnerable to Arbitrary File Write via the Zip Import feature (ZipSlip). The lack of filename validation in file.utils.ts allows an attacker to write files to arbitrary locations on the server.

Docmost is open-source collaborative wiki and documentation software. From 0.21.0 until 0.95.0, any authenticated workspace member with edit rights to a space can upload an archive to the page-import feature whose ZIP extraction routine does not limit total uncompressed size, per-entry size, or entry count. The extractor writes entries to the server temp directory and automatically extracts one nested ZIP, allowing an outer upload within the default 200 MB limit to expand by multiple GB. The resulting disk exhaustion can crash the import worker and degrade or take down the instance for all tenants. This issue is fixed in version 0.95.0.

Docmost is open-source collaborative wiki and documentation software. Prior to 0.90.1, an authenticated workspace member who does not belong to a private space can call the transclusion / sync-block lookup API with a known sourcePageId and transclusionId pair because the lookup does not enforce private space membership before resolving the source page. The API can return confidential sync-block content and source page metadata even though the normal page APIs deny access to the same page. This issue is fixed in version 0.90.1.

Docmost is open-source collaborative wiki and documentation software. From 0.70.0 until 0.80.1, a low-privileged authenticated user who can edit an exportable page can embed a forged attachmentId that belongs to a restricted page in the same space. Exporting the attacker-controlled page with includeAttachments=true causes the page export flow to read the restricted attachment from storage and include it in the returned ZIP archive even though direct file download denies access. This issue is fixed in version 0.80.1.

Docmost is open-source collaborative wiki and documentation software. Prior to 0.80.1, the public avatar and logo image endpoint accepts attacker-controlled fileName path segments and resolves them against local storage without confinement to the intended image directory. An unauthenticated attacker can traverse outside the avatar or logo directory and read local storage objects whose final basename satisfies the route's UUID check. This issue is fixed in version 0.80.1.

Docmost, open-source collaborative wiki and documentation software, prior to 0.80.1 allows authenticated users to store attacker-controlled avatarUrl values that are later reused by avatar cleanup without confinement to the intended directory on local-storage deployments. A low-privileged user can cause deletion of arbitrary local files or directories reachable by the Docmost service account. This issue is fixed in version 0.80.1.

Path Traversal in avatar attachments in Docmost v0.21.0 allows an unauthenticated malicious actor to disclose local files via a POST request to a public URL.

Docmost is open-source collaborative wiki and documentation software. In versions from 0.3.0 to 0.71.0, improper authorization 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.

In Docmost prior to 0.71.0, improper neutralization of attachment URLs allows a low-privileged authenticated user to store a malicious `javascript:` URL inside an attachment node. When another user views the page and activates the link, attacker-controlled JavaScript executes in the Docmost context.

Docmost prior to 0.70.0 is vulnerable to XSS via MIME type spoofing. An attacker can inject malicious script that executes in the victim's browser.