JenkinsApplication
CVE-2021-21607
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedJenkins 2.274 and earlier, LTS 2.263.1 and earlier does not limit sizes provided as query parameters to graph-rendering URLs, allowing attackers to request crafted URLs that use all available memory in Jenkins, potentially leading to out of memory errors.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceJenkins does not validate or limit the size of query parameters in graph-rendering URLs, allowing attackers to craft requests with extremely large values that consume all available heap memory, potentially causing out of memory errors and denial of service.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data
JenkinsApplication
<= 2.263.1<= 2.274CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Check installed Jenkins versionNavigate to Manage Jenkins > About Jenkins or access /api/json?tree=version endpoint. The version is also displayed on the login page footer.Affected if The installed version is 2.274 or lower, or 2.263.1 or lower (LTS) - specifically any version in the range <= 2.263.1 or <= 2.274
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Confirm Jenkins is exposed to networkVerify that the Jenkins web interface is accessible over HTTP/HTTPS from network locations. Check the binding configuration in jenkins.xml or startup logs for the listen address.Affected if Jenkins HTTP port is bound to a non-localhost interface (0.0.0.0 or external IP) without network access controls
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Identify graph rendering endpoint accessibilityTest access to the graph rendering URL pattern by attempting to access a build page with a large query parameter, for example: /job/JOBNAME/_lastStableBuild/artifact/path/to/file/graph?width=999999999Affected if The request returns a response rather than being rejected by a front-end proxy or web application firewall with size limits
You are affected if your Jenkins version is 2.274 or lower, or 2.263.1 or lower for LTS releases, and the web interface is network-accessible.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor dataUpgrade to Jenkins 2.274.1 or LTS 2.263.2 which contain bounds checking for graph-rendering URL parameters.
Fix this in Jenkins
Scoped from the published advisory
- Consultation2.0 h
- Implementation3.0 h
- Testing3.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,800.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-21607 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2021-21607 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data