What is CVE-2026-58489?
HedgeDoc is an open source, real-time collaborative markdown notes application. Prior to 1.11.0, the GitHub Gist export flow created an OAuth2 state value but only checked that it was present rather than validating it against the value expected for the user's session. Because the state was not properly validated, an attacker could forge a callback URL containing their own valid GitHub OAuth code. When processing the callback, HedgeDoc used the victim's logged-in session to select which note to export, but the attacker's authorization code to determine which GitHub account received it. As a result, a logged-in victim who clicked a crafted link could export their own private, protected, or limited note directly into a Gist controlled by the attacker. This issue has been fixed in version 1.11.0.
The record classifies CVE-2026-58489 under weakness class CWE-352. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 84 days ago.
Severity and exploitation probability
- CVSS v4.0 base score
- 6.8 — Medium (derived from score)
CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:A/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N - EPSS (FIRST)
- 0.1% probability of exploitation in the next 30 days, higher than 2.6% of all scored CVEs
- CISA KEV
- Not listed in the CISA Known Exploited Vulnerabilities catalog
- Threadlinqs priority
- 3.5/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- Published
- 2026-07-13, last modified 2026-07-14
Is CVE-2026-58489 being exploited?
It currently carries a trending score of 30 in the Threadlinqs vulnerability feed.
Affected products and versions
- hedgedoc: hedgedoc
How to fix CVE-2026-58489
No vendor patch reference has been recorded for CVE-2026-58489 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.
Threat activity tracking CVE-2026-58489
No threat campaign in the Threadlinqs corpus currently references CVE-2026-58489, in its CVE list or as an indicator. The linkage is recomputed from the live corpus on every daily ingest, so this section fills in as soon as a tracked campaign cites the identifier.
Sources
Enriched from CVE.org, NVD, FIRST EPSS. Last verified by Threadlinqs on . This product uses the NVD API but is not endorsed or certified by the NVD.