How severe is CVE-2020-28735?

CVE-2020-28735 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2020-28735 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (71st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-28735?

CVE-2020-28735 affects Plone. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2020-28735?

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-2020-28735 published?

CVE-2020-28735 was published on 2020-12-30 and last updated on 2026-06-17.

CVE-2020-28735

CVE-2020-28735 is a high-severity vulnerability in Plone with a CVSS 3.x base score of 8.8. 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-918.

Key facts

Severity: High (CVSS 3.x base score 8.8)
CVSS v2: 6.5
EPSS exploit prediction: 1% (71st percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-918
Affected product: Plone
Published: 2020-12-30
Last modified: 2026-06-17

Description

Plone before 5.2.3 allows SSRF attacks via the tracebacks feature (only available to the Manager role).

Frequently asked questions

What is CVE-2020-28735?: Plone before 5.2.3 allows SSRF attacks via the tracebacks feature (only available to the Manager role).
How severe is CVE-2020-28735?: CVE-2020-28735 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2020-28735 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (71st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-28735?: CVE-2020-28735 affects Plone. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2020-28735?: 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-2020-28735 published?: CVE-2020-28735 was published on 2020-12-30 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:plone:plone:*:*:*:*:*:*:*:*

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