CVE-2026-102927hedgedoc improper input validation
CVE-2026-102927 is a improper input validation in hedgedoc, rated medium (5.9 on CVSS 4.0).
Why this priority: Medium severity, with no exploitation signal.
Published · Updated · NVD status: Received
What it is
The software trusts input it should check, so crafted values reach code that assumes they are well formed. Access to a resource or action is not restricted to the people meant to have it.
How it is reached
An attacker can exploit it over the network, with an ordinary user account, but someone has to act first, such as opening a file or following a link. Success also depends on conditions the attacker does not fully control.
What an attacker gains
A successful attack can change data or behaviour. In practice, this kind of flaw lets an attacker drive the component into behaviour its authors did not intend.
Is it being exploited?
There is no public report of exploitation yet. EPSS estimates a 0.32% chance of exploitation activity in the next 30 days, higher than 25% of scored CVEs.
What to do
- Upgrade hedgedoc to 1.11.1 or later.
- Until it is patched, review who holds accounts that can reach it.
- Warn the people who use it, and filter files and links on the way in.
Description from NVD
HedgeDoc is an open source, real-time collaborative markdown notes application. Prior to 1.11.1, the WebSocket permission handler allows a note owner to store strings outside the supported freely, editable, limited, locked, protected, and private permission values. The viewing and editing checks handle only known values and can otherwise fall through to permissive behavior, making a note readable or writable more broadly than intended. SQLite deployments can persist the invalid value because the database column does not strictly enforce the set, while MySQL and PostgreSQL reject the database update but can leave the in-memory note state inconsistent for connected users until reload or cache eviction. Exploitation requires the note owner to intentionally submit an invalid permission value, and the owner could already choose a legitimate permissive setting, which limits the practical security impact. This issue is fixed in version 1.11.1.
What this means for your architecture.
A CVE names a product. Whether it matters depends on where that product sits in your systems: what reaches it, which trust boundary it guards and what it can reach once compromised. Veriom maps your components, their relationships and your trust boundaries from your code, cloud and delivery evidence, so you can see where a component like this sits. The radar itself does not look at your systems.
Components it touches
- Interfaces that accept external input. The flaw sits at the input boundary of the affected component.
- Permission checks in APIs and admin surfaces. The flaw sits between one role or tenant and another.
- Multi-tenant services. The flaw sits between one role or tenant and another.
Trust boundaries in play
- Authenticated network access. An account is needed, so exposure follows who can sign in: customers, partners or staff.
- People who open files and links. Mail, chat and browsers are the delivery path.
- At the input boundary of the affected component. An attacker who crosses it can drive the component into behaviour its authors did not intend.
- Between one role or tenant and another. An attacker who crosses it can reach data or actions their role should not allow.
Questions to answer about your own systems
- Where does hedgedoc run in your systems, and at which version?
- Which of those instances can be reached from the internet or partner networks?
- What can it reach once compromised: which data stores, secrets and services?
Sources
- CVE records and CVSS scores from the NVD CVE API. This product uses the NVD API but is not endorsed or certified by the NVD.
- Exploitation status from CISA’s Known Exploited Vulnerabilities catalog.
- Exploit likelihood from FIRST’s Exploit Prediction Scoring System (EPSS), refreshed daily.
- Explanations are written by Veriom from fixed templates over each record’s data, not by a person reviewing each CVE. Descriptions are quoted from the records as published.