CVE-2022-31108 | Arbitrary `CSS` injection into the generated graph affecting the container HTML in mermaid.js

Exp

Mermaid is a JavaScript based diagramming and charting tool that uses Markdown-inspired text definitions and a renderer to create and modify complex diagrams. An attacker is able to inject arbitrary `CSS` into the generated graph allowing them to change the styling of elements outside of the generated graph, and potentially exfiltrate sensitive information by using specially crafted `CSS` selectors. The following example shows how an attacker can exfiltrate the contents of an input field by bruteforcing the `value` attribute one character at a time. Whenever there is an actual match, an `http` request will be made by the browser in order to "load" a background image that will let an attacker know what's the value of the character. This issue may lead to `Information Disclosure` via CSS selectors and functions able to generate HTTP requests. This also allows an attacker to change the document in ways which may lead a user to perform unintended actions, such as clicking on a link, etc. This issue has been resolved in version 9.1.3. Users are advised to upgrade. Users unable to upgrade should ensure that user input is adequately escaped before embedding it in CSS blocks.

Published: 2022-06-28 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2022-31108 is rated Exploit Available (50/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 0.76%). 1 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2022-31108

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2022-31108

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.22% 0.76% +0.54%
2 2025-09-16 0.32% 0.22% -0.10%
3 2025-06-29 — 0.32% —

Full EPSS history (8 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2022-31108

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
4.1 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 2.3 1.4 [email protected]
6.1 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
 2.8 2.7 [email protected]
5.8 2.0 MEDIUM
AV:N/AC:M/Au:N/C:P/I:P/A:N Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:N)
No availability impact.
 8.6 4.9 [email protected]

Weakness enumeration for CVE-2022-31108

GitHub Security Advisory for CVE-2022-31108

GHSA-x3vm-38hw-55wf · Severity: medium · Ecosystem: npm — Possible inject arbitrary `CSS` into the generated graph affecting the container HTML

OS Trackers for CVE-2022-31108

vendor priority summary link
debian not yet assigned CVE-2022-31108 not yet assigned priority: Debian including 1 source packages (node-mermaid), 1 status rows across 1 suites (bullseye): open 1. https://security-tracker.debian.org/tracker/CVE-2022-31108
ubuntu medium CVE-2022-31108 medium priority: Ubuntu including 1 source packages (node-mermaid), 14 status rows across 14 suites (bionic, focal, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): DNE 10, ignored 2, needs-triage 1, released 1. https://ubuntu.com/security/CVE-2022-31108

Affected software / configurations for CVE-2022-31108

Vendor Product Version Raw CPE
mermaid_project mermaid >= 8.0.0, < 9.1.3 cpe:2.3:a:mermaid_project:mermaid:*:*:*:*:*:node.js:*:*

References for CVE-2022-31108

cvelogic Threat Intelligence