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Vulnerability details: VCID-9qrr-z4mp-vyfp
Vulnerability ID VCID-9qrr-z4mp-vyfp
Aliases CVE-2019-18886
GHSA-4vpc-5jx4-cfqg
Summary User enumeration leak using switch user functionality in Symfony An issue was discovered in Symfony 4.2.0 to 4.2.11 and 4.3.0 to 4.3.7. The ability to enumerate users was possible due to different handling depending on whether the user existed when making unauthorized attempts to use the switch users functionality. This is related to symfony/security.
Status Published
Exploitability 0.5
Weighted Severity 6.2
Risk 3.1
Affected and Fixed Packages Package Details
Weaknesses (4)
CWE-200 Exposure of Sensitive Information to an Unauthorized Actor
CWE-203 Observable Discrepancy
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 0.01546 https://api.first.org/data/v1/epss?cve=CVE-2019-18886
epss 0.01546 https://api.first.org/data/v1/epss?cve=CVE-2019-18886
epss 0.01546 https://api.first.org/data/v1/epss?cve=CVE-2019-18886
epss 0.01546 https://api.first.org/data/v1/epss?cve=CVE-2019-18886
epss 0.01546 https://api.first.org/data/v1/epss?cve=CVE-2019-18886
epss 0.01546 https://api.first.org/data/v1/epss?cve=CVE-2019-18886
epss 0.01546 https://api.first.org/data/v1/epss?cve=CVE-2019-18886
epss 0.01546 https://api.first.org/data/v1/epss?cve=CVE-2019-18886
epss 0.01546 https://api.first.org/data/v1/epss?cve=CVE-2019-18886
epss 0.01546 https://api.first.org/data/v1/epss?cve=CVE-2019-18886
cvssv3.1_qr MODERATE https://github.com/advisories/GHSA-4vpc-5jx4-cfqg
cvssv3.1 5.3 https://github.com/FriendsOfPHP/security-advisories/blob/master/symfony/security-http/CVE-2019-18886.yaml
generic_textual MODERATE https://github.com/FriendsOfPHP/security-advisories/blob/master/symfony/security-http/CVE-2019-18886.yaml
cvssv3.1 5.3 https://github.com/FriendsOfPHP/security-advisories/blob/master/symfony/symfony/CVE-2019-18886.yaml
generic_textual MODERATE https://github.com/FriendsOfPHP/security-advisories/blob/master/symfony/symfony/CVE-2019-18886.yaml
cvssv3.1 5.3 https://github.com/symfony/symfony/releases/tag/v4.3.8
generic_textual MODERATE https://github.com/symfony/symfony/releases/tag/v4.3.8
cvssv2 5.0 https://nvd.nist.gov/vuln/detail/CVE-2019-18886
cvssv3.1 5.3 https://nvd.nist.gov/vuln/detail/CVE-2019-18886
generic_textual MODERATE https://nvd.nist.gov/vuln/detail/CVE-2019-18886
cvssv3.1 5.3 https://symfony.com/blog/cve-2019-18886-prevent-user-enumeration-using-switch-user-functionality
generic_textual MODERATE https://symfony.com/blog/cve-2019-18886-prevent-user-enumeration-using-switch-user-functionality
cvssv3.1 5.3 https://symfony.com/blog/symfony-4-3-8-released
generic_textual MODERATE https://symfony.com/blog/symfony-4-3-8-released
cvssv3.1 5.3 https://symfony.com/cve-2019-18886
generic_textual MODERATE https://symfony.com/cve-2019-18886
Reference id Reference type URL
https://api.first.org/data/v1/epss?cve=CVE-2019-18886
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-18886
https://github.com/FriendsOfPHP/security-advisories/blob/master/symfony/security-http/CVE-2019-18886.yaml
https://github.com/FriendsOfPHP/security-advisories/blob/master/symfony/symfony/CVE-2019-18886.yaml
https://github.com/symfony/symfony/releases/tag/v4.3.8
https://nvd.nist.gov/vuln/detail/CVE-2019-18886
https://symfony.com/blog/cve-2019-18886-prevent-user-enumeration-using-switch-user-functionality
https://symfony.com/blog/symfony-4-3-8-released
https://symfony.com/cve-2019-18886
cpe:2.3:a:sensiolabs:symfony:*:*:*:*:*:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:a:sensiolabs:symfony:*:*:*:*:*:*:*:*
GHSA-4vpc-5jx4-cfqg https://github.com/advisories/GHSA-4vpc-5jx4-cfqg
No exploits are available.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N Found at https://github.com/FriendsOfPHP/security-advisories/blob/master/symfony/security-http/CVE-2019-18886.yaml
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:N/S:U/C:L/I:N/A:N Found at https://github.com/FriendsOfPHP/security-advisories/blob/master/symfony/symfony/CVE-2019-18886.yaml
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:N/S:U/C:L/I:N/A:N Found at https://github.com/symfony/symfony/releases/tag/v4.3.8
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: AV:N/AC:L/Au:N/C:P/I:N/A:N Found at https://nvd.nist.gov/vuln/detail/CVE-2019-18886
Exploitability (E) Access Vector (AV) Access Complexity (AC) Authentication (Au) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

high

functional

unproven

proof_of_concept

not_defined

local

adjacent_network

network

high

medium

low

multiple

single

none

none

partial

complete

none

partial

complete

none

partial

complete
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N Found at https://nvd.nist.gov/vuln/detail/CVE-2019-18886
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:N/S:U/C:L/I:N/A:N Found at https://symfony.com/blog/cve-2019-18886-prevent-user-enumeration-using-switch-user-functionality
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:N/S:U/C:L/I:N/A:N Found at https://symfony.com/blog/symfony-4-3-8-released
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:N/S:U/C:L/I:N/A:N Found at https://symfony.com/cve-2019-18886
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 0.81333
EPSS Score 0.01546
Published At April 1, 2026, 12:55 p.m.
Date Actor Action Source VulnerableCode Version
2026-04-01T13:04:19.784452+00:00 GithubOSV Importer Import https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2019/12/GHSA-4vpc-5jx4-cfqg/GHSA-4vpc-5jx4-cfqg.json 38.0.0