Excessive memory allocation in graph URLs leads to denial of service in Jenkins

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

6.5 · CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

EPSS

• CVE-2021-21607: 1.46% estimated exploitation activity in the next 30 days; percentile 73.64 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Jenkins renders several different graphs for features like agent and label usage statistics, memory usage, or various plugin-provided statistics. Jenkins 2.274 and earlier, LTS 2.263.1 and earlier does not limit the graph size provided as query parameters. This allows attackers to request or to have legitimate Jenkins users request crafted URLs that rapidly use all available memory in Jenkins, potentially leading to out of memory errors. Jenkins 2.275, LTS 2.263.2 limits the maximum size of graphs to an area of 10 million pixels. If a larger size is requested, the default size for the graph will be rendered instead. This threshold can be configured by setting the Java system property hudson.util.Graph.maxArea to a different number on startup.

Published by the source

24 May 2022, 17:39 UTC

Last modified by the source

14 Dec 2023, 15:40 UTC

Source last checked

26 Oct 2026, 16:21 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-cxqw-vjcr-gp5g

Preview the exact text before you copy it. Commands are read-only suggestions; review them before running anything.

# Patch Next advisory brief: CVE-2021-21607

Advisory: Excessive memory allocation in graph URLs leads to denial of service in Jenkins
IDs: CVE-2021-21607, GHSA-cxqw-vjcr-gp5g
Record: https://patchnext.com/advisories/cve-2021-21607 (revision 1, source checked 26 Oct 2026, 16:21 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: org.jenkins-ci.main:jenkins-core 2.275, 2.263.2. A vendor fix does not mean a deployment is fixed.

## Affected components
- Maven org.jenkins-ci.main:jenkins-core: affected <= 2.263.1; >= 2.264, <= 2.274; fixed in 2.275, 2.263.2

## Suggested inspection (read-only)
- Maven org.jenkins-ci.main:jenkins-core: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on org.jenkins-ci.main:jenkins-core.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-cxqw-vjcr-gp5g (GitHub-reviewed advisory GHSA-cxqw-vjcr-gp5g lists affected ranges: Maven org.jenkins-ci.main:jenkins-core >=0 =2.264 <=2.274)

Commands are suggestions: review each one before running it.