How severe is CVE-2021-4235?

CVE-2021-4235 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2021-4235 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (33rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-4235?

CVE-2021-4235 affects Yaml Project Yaml. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-4235?

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

When was CVE-2021-4235 published?

CVE-2021-4235 was published on 2022-12-27 and last updated on 2026-06-17.

CVE-2021-4235

CVE-2021-4235 is a medium-severity vulnerability in Yaml Project Yaml with a CVSS 3.x base score of 5.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Severity: Medium (CVSS 3.x base score 5.5)
EPSS exploit prediction: 0% (33rd percentile)
Actively exploited: Not listed in CISA KEV
Affected product: Yaml Project Yaml
Published: 2022-12-27
Last modified: 2026-06-17

Description

Due to unbounded alias chasing, a maliciously crafted YAML file can cause the system to consume significant system resources. If parsing user input, this may be used as a denial of service vector.

Frequently asked questions

What is CVE-2021-4235?: Due to unbounded alias chasing, a maliciously crafted YAML file can cause the system to consume significant system resources. If parsing user input, this may be used as a denial of service vector.
How severe is CVE-2021-4235?: CVE-2021-4235 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2021-4235 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (33rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-4235?: CVE-2021-4235 affects Yaml Project Yaml. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-4235?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-4235 published?: CVE-2021-4235 was published on 2022-12-27 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:yaml_project:yaml:*:*:*:*:*:go:*:*

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