HOMEVULNERABILITIESCVE-2020-26286
HIGH

CVE-2020-26286

CWE-434Published: December 29, 2020· Updated: Jun 17, 2026

7.5
CVSS v3.1

Official Description

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.

NVD Source

Technical Analysis

CVE-2020-26286 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in full integrity compromise (data manipulation), with a CVSS base score of 7.5.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.None
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityNone
IntegrityHigh
AvailabilityNone
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Affected Vendors & Products

hedgedoc1 product(s)
hedgedoc
Source: NVD CPE · 1 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

PATCHhttps://github.com/hedgedoc/hedgedoc/commit/e9306991cdb5ff2752c1eeba3fedba42aec3c2d8
PATCHhttps://github.com/hedgedoc/hedgedoc/commit/e9306991cdb5ff2752c1eeba3fedba42aec3c2d8
ADVISORYhttps://github.com/hedgedoc/hedgedoc/releases/tag/1.7.1
ADVISORYhttps://github.com/hedgedoc/hedgedoc/security/advisories/GHSA-wcr3-xhv7-8gxc
ADVISORYhttps://github.com/hedgedoc/hedgedoc/releases/tag/1.7.1
ADVISORYhttps://github.com/hedgedoc/hedgedoc/security/advisories/GHSA-wcr3-xhv7-8gxc

All References (6)

→
https://github.com/hedgedoc/hedgedoc/commit/e9306991cdb5ff2752c1eeba3fedba42aec3c2d8Patch · Third Party Advisory
→
https://github.com/hedgedoc/hedgedoc/releases/tag/1.7.1Third Party Advisory
→
https://github.com/hedgedoc/hedgedoc/security/advisories/GHSA-wcr3-xhv7-8gxcThird Party Advisory
→
https://github.com/hedgedoc/hedgedoc/commit/e9306991cdb5ff2752c1eeba3fedba42aec3c2d8Patch · Third Party Advisory
→
https://github.com/hedgedoc/hedgedoc/releases/tag/1.7.1Third Party Advisory
→
https://github.com/hedgedoc/hedgedoc/security/advisories/GHSA-wcr3-xhv7-8gxcThird Party Advisory

Quick Facts

CVE IDCVE-2020-26286
CVSS Score7.5 / 10
SeverityHIGH
WeaknessCWE-434
CISA KEVNo
Affected1 vendor(s)
PublishedDec 29, 2020

Related CVEs (CWE-434)

CVE-2023-49815
10.0
CVE-2023-23656
10.0
CVE-2021-42645
10.0
CVE-2021-38397
10.0
CVE-2022-40981
10.0
CVE-2024-31115
10.0

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2020-26286 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.
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