Security advisory
HedgeDoc is a collaborative platform for writing and sharing markdown. In HedgeDoc before version 1.7.1 an unauthenticated attacker can upload arbitrary files to the upload storage backend including HTML, JS and PHP files. The problem is patched in HedgeDoc 1.7.1. You should however verify that your uploaded file storage only contains files that are allowed, as uploaded files might still be served. As workaround it's possible to block the `/uploadimage` endpoint on your instance using your reverse proxy. And/or restrict MIME-types and file names served from your upload file storage.
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2020-26286
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 11:08 UTC · Revision 1
Source evidence
HedgeDoc is a collaborative platform for writing and sharing markdown. In HedgeDoc before version 1.7.1 an unauthenticated attacker can upload arbitrary files to the upload storage backend including HTML, JS and PHP files. The problem is patched in HedgeDoc 1.7.1. You should however verify that your uploaded file storage only contains files that are allowed, as uploaded files might still be served. As workaround it's possible to block the `/uploadimage` endpoint on your instance using your reverse proxy. And/or restrict MIME-types and file names served from your upload file storage.
osv:CVE-2020-26286
Complete source record
{
"id": "77250f77d65fa34188bdaae57767636668f635336d63384a0abe4a1e185b4146",
"url": "https://osv.dev/vulnerability/CVE-2020-26286",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "CVE-2020-26286",
"summary": "HedgeDoc is a collaborative platform for writing and sharing markdown. In HedgeDoc before version 1.7.1 an unauthenticated attacker can upload arbitrary files to the upload storage backend including HTML, JS and PHP files. The problem is patched in HedgeDoc 1.7.1. You should however verify that your uploaded file storage only contains files that are allowed, as uploaded files might still be served. As workaround it's possible to block the `/uploadimage` endpoint on your instance using your reverse proxy. And/or restrict MIME-types and file names served from your upload file storage.",
"evidence": "osv:CVE-2020-26286",
"products": [],
"severity": "high",
"structured": {
"id": "CVE-2020-26286",
"aliases": [
"CVE-2020-26286",
"GHSA-wcr3-xhv7-8gxc"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N"
}
],
"affected": [
{
"ranges": [
{
"repo": "https://github.com/hedgedoc/hedgedoc",
"type": "GIT",
"events": [
{
"introduced": "0"
},
{
"fixed": "5b3d62e494c52309765da4b420516f00d49cb753"
},
{
"fixed": "e9306991cdb5ff2752c1eeba3fedba42aec3c2d8"
}
],
"database_specific": {
"extracted_events": [
{
"cpe": "cpe:2.3:a:hedgedoc:hedgedoc:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "0"
},
{
"fixed": "1.7.1"
}
],
"source": "CPE_RANGE"
},
{
"range": [
{
"fixed": "e9306991cdb5ff2752c1eeba3fedba42aec3c2d8"
}
],
"source": "REFERENCES_COMMIT"
},
{
"range": [
{
"fixed": "5b3d62e494c52309765da4b420516f00d49cb753"
}
],
"source": "REFERENCES_TAG",
"original_tag": "1.7.1"
}
]
}
}
],
"versions": [
"1.7.0",
"1.7.0-rc2",
"1.7.0-rc1",
"1.6.0",
"1.5.0",
"1.4.0",
"1.3.2",
"1.3.1",
"1.3.0",
"1.2.1",
"1.2.0",
"1.1.1-ce",
"1.1.0-ce",
"1.0.1-ce",
"1.0.0-ce",
"0.5.0",
"0.4.6",
"0.4.5",
"0.4.4",
"0.4.3",
"0.4.2",
"0.4.1",
"0.4.0",
"v0.3.4",
"v0.3.3"
],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2020-26286.json"
}
}
],
"modified": "2026-10-20T10:52:57.346247588Z",
"provider": "osv",
"references": [
"https://github.com/hedgedoc/hedgedoc/releases/tag/1.7.1",
"https://github.com/hedgedoc/hedgedoc/security/advisories/GHSA-wcr3-xhv7-8gxc",
"https://github.com/hedgedoc/hedgedoc/commit/e9306991cdb5ff2752c1eeba3fedba42aec3c2d8"
],
"provider_metadata": {}
},
"related_cves": [
{
"value": "CVE-2020-26286",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 384089,
"published_at": "2020-12-29T00:15:12.593+00:00"
}