How severe is CVE-2021-21677?

CVE-2021-21677 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-21677 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (80th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-21677?

CVE-2021-21677 affects Jenkins Code Coverage Api. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-21677?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2021-21677 published?

CVE-2021-21677 was published on 2021-08-31 and last updated on 2026-06-17.

CVE-2021-21677

CVE-2021-21677 is a high-severity vulnerability in Jenkins Code Coverage Api with a CVSS 3.x base score of 8.8. 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-502.

Key facts

Severity: High (CVSS 3.x base score 8.8)
CVSS v2: 6.5
EPSS exploit prediction: 2% (80th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-502
Affected product: Jenkins Code Coverage Api
Published: 2021-08-31
Last modified: 2026-06-17

Description

Jenkins Code Coverage API Plugin 1.4.0 and earlier does not apply Jenkins JEP-200 deserialization protection to Java objects it deserializes from disk, resulting in a remote code execution vulnerability.

Frequently asked questions

What is CVE-2021-21677?: Jenkins Code Coverage API Plugin 1.4.0 and earlier does not apply Jenkins JEP-200 deserialization protection to Java objects it deserializes from disk, resulting in a remote code execution vulnerability.
How severe is CVE-2021-21677?: CVE-2021-21677 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-21677 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (80th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-21677?: CVE-2021-21677 affects Jenkins Code Coverage Api. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-21677?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-21677 published?: CVE-2021-21677 was published on 2021-08-31 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:jenkins:code_coverage_api:*:*:*:*:*:jenkins:*:*

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