How severe is CVE-2021-30458?

CVE-2021-30458 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2021-30458 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (58th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-30458?

CVE-2021-30458 affects Wikimedia Parsoid. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-30458?

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

When was CVE-2021-30458 published?

CVE-2021-30458 was published on 2021-04-09 and last updated on 2026-06-17.

CVE-2021-30458

CVE-2021-30458 is a medium-severity vulnerability in Wikimedia Parsoid with a CVSS 3.x base score of 6.1. 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-79.

Key facts

Severity: Medium (CVSS 3.x base score 6.1)
CVSS v2: 4.3
EPSS exploit prediction: 1% (58th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-79
Affected product: Wikimedia Parsoid
Published: 2021-04-09
Last modified: 2026-06-17

Description

An issue was discovered in Wikimedia Parsoid before 0.11.1 and 0.12.x before 0.12.2. An attacker can send crafted wikitext that Utils/WTUtils.php will transform by using a <meta> tag, bypassing sanitization steps, and potentially allowing for XSS.

Frequently asked questions

What is CVE-2021-30458?: An issue was discovered in Wikimedia Parsoid before 0.11.1 and 0.12.x before 0.12.2. An attacker can send crafted wikitext that Utils/WTUtils.php will transform by using a <meta> tag, bypassing sanitization steps, and potentially allowing for XSS.
How severe is CVE-2021-30458?: CVE-2021-30458 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2021-30458 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (58th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-30458?: CVE-2021-30458 affects Wikimedia Parsoid. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-30458?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-30458 published?: CVE-2021-30458 was published on 2021-04-09 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:wikimedia:parsoid:*:*:*:*:*:node.js:*:*

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