CVE-2024-45308: HedgeDoc is an open source, real-time, collaborative, markdown notes application.

HedgeDoc is an open source, real-time, collaborative, markdown notes application.

HedgeDoc is an open source, real-time, collaborative, markdown notes application. When using HedgeDoc 1 with MySQL or MariaDB, it is possible to create notes with an alias matching the ID of existing notes. The affected existing note can then not be accessed anymore and is effectively hidden by the new one. When the freeURL feature is enabled (by setting the `allowFreeURL` config option or the `CMD_ALLOW_FREEURL` environment variable to `true`), any user with the appropriate permissions can create a note with an arbitrary alias, e.g. by accessing it in the browser. When MySQL or MariaDB are used, it is possible to create a new note with an alias that matches the lower-cased ID of a different note. HedgeDoc then always presents the new note to users, as these databases perform case-insensitive matching and the lower-cased alias is found first. This issue only affects HedgeDoc instances that use MySQL or MariaDB. Depending on the permission settings of the HedgeDoc instance, the issue can be exploited only by logged-in users or by all (including non-logged-in) users. The exploit requires knowledge of the ID of the target note. Attackers could use this issue to present a manipulated c

Description from the National Vulnerability Database, published by GitHub

What it means for a small business

If your business uses hedgedoc, install the vendor's update. If you're not sure whether you use it, ask whoever manages your computers.

How likely is an attack? The Exploit Prediction Scoring System, run by FIRST (the global association of security response teams), puts the odds of this one being exploited in the next 30 days at 0.55%, higher than 45% of CVEs. That’s low, but low isn’t zero, and the odds jump the day someone publishes an exploit. Scored October 28, 2026, updated daily.

Check your own setup

Website check: reads what your site runs from the outside (WordPress version, plugins it can see, old server software) and matches it against this database.
Server check: what your web server says about itself, and whether that version has known flaws.

Sources

Part of the Huttenlocher Technologies vulnerability database, refreshed twice a day from CISA and the NVD. The title, category and plain-language guidance are ours; check the linked record before acting on a detail. This is general guidance, not a review of your systems.

Weekly security brief

The flaws that hit local websites, every Friday.

One short email: what got exploited this week, which WordPress plugins broke, and what to check. Unsubscribe in one click.