CVE-2021-33507 json
Cross-site scripting in Products.CMFCore, Products.PluggableAuthService, Plone
published 2021-05-21 5 y ago modified 2026-07-13 3 mo ago also GHSA-35rg-466w-77h3 , PYSEC-2021-79 , PYSEC-2026-2961 , PYSEC-2026-2967 , EUVD-2021-0189
- cvss
- 6.1
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.8%
- EPSS 0.8% chance of exploitation in 30 days, percentile 55%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- pypi products-cmfcore 2.5.1
- pypi products-pluggableauthservice 2.6.2
- pypi plone 5.2.5
- zope zope 2.5.1
Exploit prediction
0.75% chance of exploitation in the next 30 days, higher than 55% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| NVD | 3.1 | 6.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N |
| NVD | 2.0 | 4.3 | AV:N/AC:M/Au:N/C:N/I:P/A:N |
| OSV | 3.1 | 6.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N |
| GitHub | 3.1 | 6.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| pypi | products-cmfcore | <2.5.1 |
2.5.1 |
| pypi | products-pluggableauthservice | <2.6.2 |
2.6.2 |
| pypi | plone | <=5.2.4 <5.2.5 |
5.2.5 |
Classification
- Weakness
-
- CWE-79 Improper Neutralization of Input During Web Page Generation
References
-
plone.org
/security/hotfix/20210518/reflected-xss-in-various-spots
web, vendor-advisory
-
openwall.com
/lists/oss-security/2021/05/22/1
mailing-list, web, third-party-advisory
-
nvd.nist.gov
/vuln/detail/CVE-2021-33507
advisory
-
github.com
/advisories/GHSA-35rg-466w-77h3
advisory
-
github.com
/pypa/advisory-database/tree/main/vulns/plone/PYSEC-2021-79.yaml
web
-
pypi.org
/project/products-pluggableauthservice
package
-
pypi.org
/project/products-cmfcore
package
Sources
- CVE List CVE-2021-33507
- GitHub Advisory GHSA-35rg-466w-77h3
- NVD CVE-2021-33507
- OSV PYSEC-2026-2967
- OSV PYSEC-2021-79
- OSV PYSEC-2026-2961
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.