CVE-2023-28626Public exploitNetwork attack vector

Service interruption via quadratic Markdown parsing

Published Mar 28, 2023 · Updated Feb 18, 2025

Uncontrolled resource consumption in Comrak before 0.17.0 allows remote attackers to interrupt services via crafted Markdown. Its inline, emphasis, link, HTML, list, reference, and autolink parsing paths repeatedly process pathological constructs, producing quadratic CPU growth. Exposure requires an application to pass attacker-controlled Markdown to Comrak; processing can monopolize CPU and delay or deny service without affecting data confidentiality or integrity.

CVSS severity5.3
Medium
EPSS probability1.12%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Uncontrolled resource consumption in Comrak before 0.17.0 allows remote attackers to interrupt services via crafted Markdown. Its inline, emphasis, link, HTML, list, reference, and autolink parsing paths repeatedly process pathological constructs, producing quadratic CPU growth. Exposure requires an application to pass attacker-controlled Markdown to Comrak; processing can monopolize CPU and delay or deny service without affecting data confidentiality or integrity.

The record

CVE
CVE-2023-28626
Published
Mar 28, 2023
Updated
Feb 18, 2025
Vendor
kivikakk
Product
Comrak
Classifications
CWE-400, T1499.003
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 28, 2023CVE publishedPublication date reported by the CVE source.
  2. Feb 18, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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

  1. Affected versionversion=< 0.17.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

kivikakk · Comrakversion=< 0.17.0

Published CVSS scores

5.3GitHub CNACVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

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.

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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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-400Uncontrolled Resource Consumption
T1499.003Application Exhaustion Flood

Public exploit references

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

Technologies

Your stack

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Your stack

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