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Vulnerability details: VCID-kf3a-yce1-auh4
Vulnerability ID VCID-kf3a-yce1-auh4
Aliases CVE-2021-21691
GHSA-2c79-h2h5-g3fw
Summary Incorrect Authorization Creating symbolic links is possible without the 'symlink' agent-to-controller access control permission in Jenkins.
Status Published
Exploitability 0.5
Weighted Severity 9.0
Risk 4.5
Affected and Fixed Packages Package Details
Weaknesses (5)
CWE-1035 OWASP Top Ten 2017 Category A9 - Using Components with Known Vulnerabilities
CWE-59 Improper Link Resolution Before File Access ('Link Following')
CWE-937 OWASP Top Ten 2013 Category A9 - Using Components with Known Vulnerabilities
CWE-863 Incorrect Authorization
CWE-276 Incorrect Default Permissions
System Score Found at
cvssv3 9.0 https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2021-21691.json
epss 0.00637 https://api.first.org/data/v1/epss?cve=CVE-2021-21691
epss 0.00637 https://api.first.org/data/v1/epss?cve=CVE-2021-21691
epss 0.00637 https://api.first.org/data/v1/epss?cve=CVE-2021-21691
epss 0.00637 https://api.first.org/data/v1/epss?cve=CVE-2021-21691
epss 0.00637 https://api.first.org/data/v1/epss?cve=CVE-2021-21691
epss 0.00637 https://api.first.org/data/v1/epss?cve=CVE-2021-21691
epss 0.00637 https://api.first.org/data/v1/epss?cve=CVE-2021-21691
epss 0.00637 https://api.first.org/data/v1/epss?cve=CVE-2021-21691
epss 0.00637 https://api.first.org/data/v1/epss?cve=CVE-2021-21691
epss 0.00637 https://api.first.org/data/v1/epss?cve=CVE-2021-21691
epss 0.00637 https://api.first.org/data/v1/epss?cve=CVE-2021-21691
epss 0.00637 https://api.first.org/data/v1/epss?cve=CVE-2021-21691
epss 0.00637 https://api.first.org/data/v1/epss?cve=CVE-2021-21691
epss 0.00637 https://api.first.org/data/v1/epss?cve=CVE-2021-21691
cvssv3.1_qr CRITICAL https://github.com/advisories/GHSA-2c79-h2h5-g3fw
cvssv3.1 9.0 https://github.com/jenkinsci/jenkins
generic_textual CRITICAL https://github.com/jenkinsci/jenkins
cvssv3.1 9.0 https://github.com/jenkinsci/jenkins/commit/63cde2daadc705edf086f2213b48c8c547f98358
generic_textual CRITICAL https://github.com/jenkinsci/jenkins/commit/63cde2daadc705edf086f2213b48c8c547f98358
cvssv3.1 9.0 https://nvd.nist.gov/vuln/detail/CVE-2021-21691
generic_textual CRITICAL https://nvd.nist.gov/vuln/detail/CVE-2021-21691
archlinux Critical https://security.archlinux.org/AVG-2526
cvssv3.1 9.0 https://www.jenkins.io/security/advisory/2021-11-04/#SECURITY-2455
generic_textual CRITICAL https://www.jenkins.io/security/advisory/2021-11-04/#SECURITY-2455
Reference id Reference type URL
https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2021-21691.json
https://api.first.org/data/v1/epss?cve=CVE-2021-21691
https://github.com/jenkinsci/jenkins
https://github.com/jenkinsci/jenkins/commit/63cde2daadc705edf086f2213b48c8c547f98358
https://www.jenkins.io/security/advisory/2021-11-04/#SECURITY-2455
2020338 https://bugzilla.redhat.com/show_bug.cgi?id=2020338
ASA-202111-1 https://security.archlinux.org/ASA-202111-1
AVG-2526 https://security.archlinux.org/AVG-2526
CVE-2021-21691 https://nvd.nist.gov/vuln/detail/CVE-2021-21691
GHSA-2c79-h2h5-g3fw https://github.com/advisories/GHSA-2c79-h2h5-g3fw
RHSA-2021:4799 https://access.redhat.com/errata/RHSA-2021:4799
RHSA-2021:4801 https://access.redhat.com/errata/RHSA-2021:4801
RHSA-2021:4827 https://access.redhat.com/errata/RHSA-2021:4827
RHSA-2021:4829 https://access.redhat.com/errata/RHSA-2021:4829
RHSA-2021:4833 https://access.redhat.com/errata/RHSA-2021:4833
No exploits are available.
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H Found at https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2021-21691.json
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:C/C:H/I:H/A:H Found at https://github.com/jenkinsci/jenkins
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:C/C:H/I:H/A:H Found at https://github.com/jenkinsci/jenkins/commit/63cde2daadc705edf086f2213b48c8c547f98358
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:C/C:H/I:H/A:H Found at https://nvd.nist.gov/vuln/detail/CVE-2021-21691
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:C/C:H/I:H/A:H Found at https://www.jenkins.io/security/advisory/2021-11-04/#SECURITY-2455
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 0.70409
EPSS Score 0.00637
Published At April 1, 2026, 12:55 p.m.
Date Actor Action Source VulnerableCode Version
2026-04-01T12:49:00.140162+00:00 GitLab Importer Import https://gitlab.com/gitlab-org/advisories-community/-/blob/main/maven/org.jenkins-ci.main/jenkins-core/CVE-2021-21691.yml 38.0.0