CVE-2026-58486Network attack vector

Service hang via YAML alias expansion

Published Jul 13, 2026 · Updated Jul 13, 2026

Denial of service in HedgeDoc before 1.11.0 allows remote authenticated users to hang the service by opening a crafted note. The @hedgedoc/meta-marked frontmatter path calls js-yaml.load from js-yaml v3, recursively resolving anchor aliases into a CPU-intensive object graph. An attacker must be able to create a note; publish or editor requests re-expand the stored payload and can block the Node.js event loop across process restarts.

CVSS severity8.3
High
EPSS probability0.40%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Denial of service in HedgeDoc before 1.11.0 allows remote authenticated users to hang the service by opening a crafted note. The @hedgedoc/meta-marked frontmatter path calls js-yaml.load from js-yaml v3, recursively resolving anchor aliases into a CPU-intensive object graph. An attacker must be able to create a note; publish or editor requests re-expand the stored payload and can block the Node.js event loop across process restarts.

The record

CVE
CVE-2026-58486
Published
Jul 13, 2026
Updated
Jul 13, 2026
Vendor
HedgeDoc
Product
HedgeDoc
Classifications
CWE-400, CWE-409, T1499.004
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 13, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 13, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 1.11.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

HedgeDoc · HedgeDocversion=< 1.11.0

Published CVSS scores

8.3GitHub, Inc.CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-400Uncontrolled Resource Consumption
CWE-409Improper Handling of Highly Compressed Data (Data Amplification)
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo