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 tag, bypassing sanitization steps, and potentially allowing for XSS.
CVE-2021-30458
MEDIUMNVD 6.16.1—
EchelonGraph scoreMEDIUM confidence
This medium-severity CVE scores 6.1 under NVD CVSS v3. EPSS exploit probability: 0.4%, top 41% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
Triggered by: NVD CVSS baseline
Sources: epss, nvd
6.1
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
- Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 1%CVSS: 6.1Exploit: NoneExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 6.1
- EG Score
- 6.1(medium)
- EPSS
- 58.1%
- KEV
- Not listed
Published
April 9, 2021
Last Modified
November 21, 2024
References (6)
- cve@mitrehttps://phabricator.wikimedia.org/T279451
- cve@mitrehttps://security.gentoo.org/glsa/202107-40
- cve@mitrehttps://www.mediawiki.org/wiki/Parsoid
- af854a3a-2127-422b-91ae-364da2661108https://phabricator.wikimedia.org/T279451
- af854a3a-2127-422b-91ae-364da2661108https://security.gentoo.org/glsa/202107-40
- af854a3a-2127-422b-91ae-364da2661108https://www.mediawiki.org/wiki/Parsoid
Affected Packages
(1 across 1 ecosystem)
Packagist(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| wikimedia/parsoid | v0.11.0 | 0.11.1 | — |
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Related CVEs(same CWE)
Frequently asked(5)
What is CVE-2021-30458?
CVE-2021-30458 is a medium vulnerability published on April 9, 2021. 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.
When was CVE-2021-30458 disclosed?
CVE-2021-30458 was first published in the National Vulnerability Database on April 9, 2021, with the most recent update on November 21, 2024. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2021-30458 actively exploited?
CVE-2021-30458 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 58.1% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2021-30458?
CVE-2021-30458 has a CVSS v3 base score of 6.1 (NVD).
How do I remediate CVE-2021-30458?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-30458, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2021-30458
Is Your Infrastructure Affected by CVE-2021-30458?
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