CVE-2021-33507

MEDIUMNVD 6.16.1—

6.1

Zope Products.CMFCore before 2.5.1 and Products.PluggableAuthService before 2.6.2, as used in Plone through 5.2.4 and other products, allow Reflected XSS.

CVSS v3: 6.1
EG Score: 6.1(medium)
EPSS: 52.1%
KEV: Not listed

Published

May 21, 2021

Last Modified

November 21, 2024

References (4)

cve@mitrehttp://www.openwall.com/lists/oss-security/2021/05/22/1
cve@mitrehttps://plone.org/security/hotfix/20210518/reflected-xss-in-various-spots
af854a3a-2127-422b-91ae-364da2661108http://www.openwall.com/lists/oss-security/2021/05/22/1
af854a3a-2127-422b-91ae-364da2661108https://plone.org/security/hotfix/20210518/reflected-xss-in-various-spots

Affected Packages

(3 across 1 ecosystem)

PyPI(3)

Package	Vulnerable range	Fixed in	Dependents
plone	3.2 ... 5.2rc5 (145 versions)	5.2.5	—
products-cmfcore	2.1.1 ... 2.5.0 (42 versions)	2.5.1	—
products-pluggableauthservice	1.10.0 ... 2.6.1 (46 versions)	2.6.2	—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

CWE-79Cross-site Scripting (XSS)

Data Freshness Timeline

(refreshed 8× in last 7d / 8× in last 30d)

Every time one of our enrichment pipelines (NVD, MITRE cvelistV5, EPSS, CISA KEV, GHSA, OSV, vendor advisories) ran against this CVE. Most recent first.

2026-05-27 13:39 UTCepss_batch
2026-05-27 13:39 UTCepss_batch
2026-05-27 13:39 UTCepss_batch
2026-05-26 16:16 UTCEG score recompute
2026-05-26 13:42 UTCepss_batch
2026-05-26 07:17 UTCepss_batch
2026-05-26 07:17 UTCepss_batch
2026-05-26 07:17 UTCepss_batch

Frequently asked(5)

What is CVE-2021-33507?

CVE-2021-33507 is a medium vulnerability published on May 21, 2021. Zope Products.CMFCore before 2.5.1 and Products.PluggableAuthService before 2.6.2, as used in Plone through 5.2.4 and other products, allow Reflected XSS.

When was CVE-2021-33507 disclosed?

CVE-2021-33507 was first published in the National Vulnerability Database on May 21, 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-2021-33507 actively exploited?

CVE-2021-33507 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 52.1% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.

What is the CVSS score of CVE-2021-33507?

CVE-2021-33507 has a CVSS v3 base score of 6.1 (NVD).

How do I remediate CVE-2021-33507?

Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-33507, 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-2021-33507

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