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Vulnerability details: VCID-5nk4-urbw-suee
Vulnerability ID VCID-5nk4-urbw-suee
Aliases CVE-2020-36321
GHSA-49r2-73m6-pp8f
Summary Path Traversal Improper URL validation in development mode handler in `com.vaadin:flow-server` allows attacker to request arbitrary files stored outside of intended frontend resources folder.
Status Published
Exploitability 0.5
Weighted Severity 6.2
Risk 3.1
Affected and Fixed Packages Package Details
Weaknesses (4)
CWE-1035 OWASP Top Ten 2017 Category A9 - Using Components with Known Vulnerabilities
CWE-22 Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
CWE-937 OWASP Top Ten 2013 Category A9 - Using Components with Known Vulnerabilities
CWE-20 Improper Input Validation
System Score Found at
epss 0.00551 https://api.first.org/data/v1/epss?cve=CVE-2020-36321
cvssv3.1 5.9 https://github.com/vaadin/flow/pull/9392
generic_textual MODERATE https://github.com/vaadin/flow/pull/9392
cvssv3.1 5.9 https://github.com/vaadin/flow/security/advisories/GHSA-49r2-73m6-pp8f
generic_textual MODERATE https://github.com/vaadin/flow/security/advisories/GHSA-49r2-73m6-pp8f
cvssv3.1 5.9 https://nvd.nist.gov/vuln/detail/CVE-2020-36321
generic_textual MODERATE https://nvd.nist.gov/vuln/detail/CVE-2020-36321
cvssv3.1 5.9 https://vaadin.com/security/cve-2020-36321
generic_textual MODERATE https://vaadin.com/security/cve-2020-36321
Reference id Reference type URL
https://api.first.org/data/v1/epss?cve=CVE-2020-36321
https://github.com/vaadin/flow/pull/9392
https://github.com/vaadin/flow/security/advisories/GHSA-49r2-73m6-pp8f
CVE-2020-36321 https://nvd.nist.gov/vuln/detail/CVE-2020-36321
CVE-2020-36321 https://vaadin.com/security/cve-2020-36321
No exploits are available.
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N Found at https://github.com/vaadin/flow/pull/9392
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:H/PR:N/UI:N/S:U/C:H/I:N/A:N Found at https://github.com/vaadin/flow/security/advisories/GHSA-49r2-73m6-pp8f
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:H/PR:N/UI:N/S:U/C:H/I:N/A:N Found at https://nvd.nist.gov/vuln/detail/CVE-2020-36321
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:H/PR:N/UI:N/S:U/C:H/I:N/A:N Found at https://vaadin.com/security/cve-2020-36321
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 0.68345
EPSS Score 0.00551
Published At June 4, 2026, 12:55 p.m.
Date Actor Action Source VulnerableCode Version
2026-06-04T16:21:05.227327+00:00 GitLab Importer Import https://gitlab.com/gitlab-org/advisories-community/-/blob/main/maven/com.vaadin/vaadin-server/CVE-2020-36321.yml 38.6.0