How severe is CVE-2021-21607?

CVE-2021-21607 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2021-21607 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (70th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-21607?

CVE-2021-21607 primarily affects Jenkins. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-21607?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-21607 published?

CVE-2021-21607 was published on 2021-01-13 and last updated on 2026-06-17.

CVE-2021-21607

CVE-2021-21607 is a medium-severity vulnerability in Jenkins with a CVSS 3.x base score of 6.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-770.

Key facts

Severity: Medium (CVSS 3.x base score 6.5)
CVSS v2: 4.0
EPSS exploit prediction: 1% (70th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-770
Affected product: Jenkins
Published: 2021-01-13
Last modified: 2026-06-17

Description

Jenkins 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.

Frequently asked questions

What is CVE-2021-21607?: Jenkins 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.
How severe is CVE-2021-21607?: CVE-2021-21607 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2021-21607 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (70th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-21607?: CVE-2021-21607 primarily affects Jenkins. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-21607?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-21607 published?: CVE-2021-21607 was published on 2021-01-13 and last updated on 2026-06-17.

References

https://www.jenkins.io/security/advisory/2021-01-13/#SECURITY-2025

Affected products (2)

cpe:2.3:a:jenkins:jenkins:*:*:*:*:lts:*:*:*
cpe:2.3:a:jenkins:jenkins:*:*:*:*:-:*:*:*

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