Jenkins Diagnostic page exposed session cookies
Jenkins shows various technical details about the current user on the /whoAmI page. In a previous fix, the Cookie header value containing the HTTP session ID was redacted. However, user metadata shown on this page could also include the HTTP session ID in Jenkins 2.218 and earlier, LTS 2.204.1 and earlier.
This allows attackers able to exploit a cross-site scripting vulnerability to obtain the HTTP session ID value from this page.
Jenkins 2.219, LTS 2.204.2 no longer prints out the affected user metadata that might contain the HTTP session ID.
Additionally, we also redact values of further authentication-related HTTP headers in addition to Cookie on this page as a hardening.
Affected software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| Java / Kotlin (Maven) | org.jenkins-ci.main:jenkins-core | >= 2.205, < 2.219, < 2.204.2 | 2.219, 2.204.2 |
References
- https://nvd.nist.gov/vuln/detail/CVE-2020-2103
- https://github.com/jenkinsci/jenkins/commit/77f36f37f5e3cabd0e4ece16d46d7943454ed15b
- https://access.redhat.com/errata/RHBA-2020:0402
- https://access.redhat.com/errata/RHBA-2020:0675
- https://access.redhat.com/errata/RHSA-2020:0681
- https://access.redhat.com/errata/RHSA-2020:0683
- https://github.com/jenkinsci/jenkins
- https://jenkins.io/security/advisory/2020-01-29/#SECURITY-1695
- http://www.openwall.com/lists/oss-security/2020/01/29/1
- CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N- Weakness (CWE)
CWE-200- Platform
- Java / Kotlin (Maven)
- Package
org.jenkins-ci.main:jenkins-core- Disclosed
- 24.05.2022
- Updated
- 11.10.2026 11:21
Sources and licenses
OSV / GitHub Advisory Database - GHSA-4jjj-cm7q-v6hr - CC BY 4.0
Vulnerability history: org.jenkins-ci.main:jenkins-core
All published vulnerabilities of this package (Java / Kotlin (Maven)), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 259
- First → latest
- 01.2022 06.2026
- Without a fix
- 1
- Exploited in attacks
- 4
Severity breakdown
- Critical 19
- High 62
- Medium 158
- Low 20
Disclosures per year
- 2022: 213
- 2023: 14
- 2024: 6
- 2025: 14
- 2026: 12
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Jenkins Diagnostic page exposed session cookies this entry
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