Non-constant time HMAC comparison
Jenkins 2.218 and earlier, LTS 2.204.1 and earlier does not use a constant-time comparison when checking whether two HMACs are equal. This could potentially allow attackers to use statistical methods to obtain a valid HMAC for an attacker-controlled input value.
Jenkins 2.219, LTS 2.204.2 now uses a constant-time comparison when validating HMACs.
Affected software
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| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| Java / Kotlin (Maven) | org.jenkins-ci.main:jenkins-core | < 2.204.2, >= 2.205, < 2.219 | 2.204.2, 2.219 |
References
- https://nvd.nist.gov/vuln/detail/CVE-2020-2102
- https://github.com/jenkinsci/jenkins/commit/6f35dbb939ebe947bdb1979010b208480f1d0e31
- 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-1660
- http://www.openwall.com/lists/oss-security/2020/01/29/1
- CVSS vector
CVSS:3.0/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N- Weakness (CWE)
CWE-203, CWE-208- 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-fj6f-6933-839j - 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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Non-constant time HMAC comparison this entry
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