CVE-2022-31108Public exploitNetwork attack vector

Information disclosure via unsanitized theme variables

Published Jun 28, 2022 · Updated Apr 22, 2025

CSS injection in Mermaid 8.0.0 through 9.1.2 allows remote authenticated users to disclose browser data through crafted diagrams. The getStyles routine inserts the textColor theme variable and other configuration values into generated style rules without sanitizing CSS metacharacters. A user must render the attacker-controlled diagram; injected selectors can probe DOM attributes through outbound image requests or restyle elements outside the graph.

CVSS severity4.1
Medium
EPSS probability0.91%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

CSS injection in Mermaid 8.0.0 through 9.1.2 allows remote authenticated users to disclose browser data through crafted diagrams. The getStyles routine inserts the textColor theme variable and other configuration values into generated style rules without sanitizing CSS metacharacters. A user must render the attacker-controlled diagram; injected selectors can probe DOM attributes through outbound image requests or restyle elements outside the graph.

The record

CVE
CVE-2022-31108
Published
Jun 28, 2022
Updated
Apr 22, 2025
Vendor
Mermaid
Product
Mermaid
Classifications
CWE-74, CWE-79
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 28, 2022CVE publishedPublication date reported by the CVE source.
  2. Apr 22, 2025Record 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=>= 8.0.0, < 9.1.3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Mermaid · Mermaidversion=>= 8.0.0, < 9.1.3

Published CVSS scores

5.8National Institute of Standards and TechnologyAV:N/AC:M/Au:N/C:P/I:P/A:N
4.1GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:N/A:N
6.1National Institute of Standards and TechnologyCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

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 exploitPublished

Weakness, pattern, technique

CWE-74Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')
CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

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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