How severe is CVE-2021-21278?

CVE-2021-21278 has a CVSS 3.x base score of 8.6, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2021-21278 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (72nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-21278?

CVE-2021-21278 affects Rsshub. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-21278?

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-2021-21278 published?

CVE-2021-21278 was published on 2021-01-26 and last updated on 2026-06-17.

CVE-2021-21278

CVE-2021-21278 is a high-severity vulnerability in Rsshub with a CVSS 3.x base score of 8.6. 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-74.

Key facts

Severity: High (CVSS 3.x base score 8.6)
CVSS v2: 7.5
EPSS exploit prediction: 2% (72nd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-74
Affected product: Rsshub
Published: 2021-01-26
Last modified: 2026-06-17

Description

RSSHub is an open source, easy to use, and extensible RSS feed generator. In RSSHub before version 7f1c430 (non-semantic versioning) there is a risk of code injection. Some routes use `eval` or `Function constructor`, which may be injected by the target site with unsafe code, causing server-side security issues The fix in version 7f1c430 is to temporarily remove the problematic route and added a `no-new-func` rule to eslint.

Frequently asked questions

What is CVE-2021-21278?: RSSHub is an open source, easy to use, and extensible RSS feed generator. In RSSHub before version 7f1c430 (non-semantic versioning) there is a risk of code injection. Some routes use `eval` or `Function constructor`, which may be injected by the target site with unsafe code, causing server-side security issues The fix in version 7f1c430 is to temporarily remove the problematic route and added a `no-new-func` rule to eslint.
How severe is CVE-2021-21278?: CVE-2021-21278 has a CVSS 3.x base score of 8.6, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2021-21278 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (72nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-21278?: CVE-2021-21278 affects Rsshub. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-21278?: 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-2021-21278 published?: CVE-2021-21278 was published on 2021-01-26 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:rsshub:rsshub:*:*:*:*:*:node.js:*:*

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