CVE-2026-58486
YAML alias bomb in HedgeDoc (<1.11.0) can cause server-wide DoS via published notes.
Is CVE-2026-58486 being exploited?
Not confirmed. CVE-2026-58486 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.40% probability of exploitation in the next 30 days.
How severe is CVE-2026-58486?
CVE-2026-58486 is rated High with a CVSS score of 8.3. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-58486?
Yes. A fix has been recorded for CVE-2026-58486. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-58486 affect?
CVE-2026-58486 affects HedgeDoc < 1.11.0, HedgeDoc publish view (/s/<shortid>), HedgeDoc editor view (/<noteId>). Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-58486?
Upgrade to HedgeDoc 1.11.0+, remove suspicious notes, and validate frontmatter parsing.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Remote attacker can embed a YAML alias bomb in note frontmatter to block Node.js event loop (~235s), causing persistent DoS until note removal.
Immediate action required
- affected< 1.11.0
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.