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Vulnerability details: VCID-x94b-cysu-4fbe
Vulnerability ID VCID-x94b-cysu-4fbe
Aliases CVE-2021-35513
GHSA-4f6x-49g2-99fm
Summary Cross-site Scripting in Mermaid Mermaid before 8.11.0 allows XSS when the antiscript feature is used.
Status Published
Exploitability 0.5
Weighted Severity 6.2
Risk 3.1
Affected and Fixed Packages Package Details
Weaknesses (3)
CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CWE-1035 OWASP Top Ten 2017 Category A9 - Using Components with Known Vulnerabilities
CWE-937 OWASP Top Ten 2013 Category A9 - Using Components with Known Vulnerabilities
System Score Found at
epss 0.00307 https://api.first.org/data/v1/epss?cve=CVE-2021-35513
epss 0.00307 https://api.first.org/data/v1/epss?cve=CVE-2021-35513
epss 0.00307 https://api.first.org/data/v1/epss?cve=CVE-2021-35513
epss 0.00307 https://api.first.org/data/v1/epss?cve=CVE-2021-35513
epss 0.00307 https://api.first.org/data/v1/epss?cve=CVE-2021-35513
epss 0.00307 https://api.first.org/data/v1/epss?cve=CVE-2021-35513
epss 0.00307 https://api.first.org/data/v1/epss?cve=CVE-2021-35513
epss 0.00307 https://api.first.org/data/v1/epss?cve=CVE-2021-35513
epss 0.00307 https://api.first.org/data/v1/epss?cve=CVE-2021-35513
epss 0.00307 https://api.first.org/data/v1/epss?cve=CVE-2021-35513
epss 0.00307 https://api.first.org/data/v1/epss?cve=CVE-2021-35513
epss 0.00307 https://api.first.org/data/v1/epss?cve=CVE-2021-35513
epss 0.00307 https://api.first.org/data/v1/epss?cve=CVE-2021-35513
epss 0.00307 https://api.first.org/data/v1/epss?cve=CVE-2021-35513
epss 0.00307 https://api.first.org/data/v1/epss?cve=CVE-2021-35513
cvssv3.1_qr MODERATE https://github.com/advisories/GHSA-4f6x-49g2-99fm
cvssv3.1 6.1 https://github.com/mermaid-js/mermaid/issues/2122
generic_textual MODERATE https://github.com/mermaid-js/mermaid/issues/2122
cvssv3.1 6.1 https://github.com/mermaid-js/mermaid/pull/2123
generic_textual MODERATE https://github.com/mermaid-js/mermaid/pull/2123
cvssv3.1 6.1 https://github.com/mermaid-js/mermaid/pull/2123/commits/3d22fa5d2435de5acc18de6f88474a6e8675a60e
generic_textual MODERATE https://github.com/mermaid-js/mermaid/pull/2123/commits/3d22fa5d2435de5acc18de6f88474a6e8675a60e
cvssv3.1 6.1 https://github.com/mermaid-js/mermaid/releases/tag/8.11.0-rc2
generic_textual MODERATE https://github.com/mermaid-js/mermaid/releases/tag/8.11.0-rc2
cvssv3.1 6.1 https://nvd.nist.gov/vuln/detail/CVE-2021-35513
generic_textual MODERATE https://nvd.nist.gov/vuln/detail/CVE-2021-35513
Reference id Reference type URL
https://api.first.org/data/v1/epss?cve=CVE-2021-35513
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-35513
https://github.com/mermaid-js/mermaid/issues/2122
https://github.com/mermaid-js/mermaid/pull/2123
https://github.com/mermaid-js/mermaid/pull/2123/commits/3d22fa5d2435de5acc18de6f88474a6e8675a60e
https://github.com/mermaid-js/mermaid/releases/tag/8.11.0-rc2
https://nvd.nist.gov/vuln/detail/CVE-2021-35513
990449 https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=990449
GHSA-4f6x-49g2-99fm https://github.com/advisories/GHSA-4f6x-49g2-99fm
No exploits are available.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N Found at https://github.com/mermaid-js/mermaid/issues/2122
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N Found at https://github.com/mermaid-js/mermaid/pull/2123
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N Found at https://github.com/mermaid-js/mermaid/pull/2123/commits/3d22fa5d2435de5acc18de6f88474a6e8675a60e
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N Found at https://github.com/mermaid-js/mermaid/releases/tag/8.11.0-rc2
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N Found at https://nvd.nist.gov/vuln/detail/CVE-2021-35513
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Exploit Prediction Scoring System (EPSS)
Percentile 0.53832
EPSS Score 0.00307
Published At April 1, 2026, 12:55 p.m.
Date Actor Action Source VulnerableCode Version
2026-04-01T13:01:09.868314+00:00 GithubOSV Importer Import https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2021/12/GHSA-4f6x-49g2-99fm/GHSA-4f6x-49g2-99fm.json 38.0.0