How severe is CVE-2020-5528?

CVE-2020-5528 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-2020-5528 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (53rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-5528?

CVE-2020-5528 primarily affects Sixapart Movable Type. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2020-5528?

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

When was CVE-2020-5528 published?

CVE-2020-5528 was published on 2020-02-06 and last updated on 2026-06-17.

CVE-2020-5528

CVE-2020-5528 is a medium-severity vulnerability in Sixapart Movable Type 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% (53rd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-79
Affected product: Sixapart Movable Type
Published: 2020-02-06
Last modified: 2026-06-17

Description

Cross-site scripting vulnerability in Movable Type series (Movable Type 7 r.4603 and earlier (Movable Type 7), Movable Type 6.5.2 and earlier (Movable Type 6.5), Movable Type Advanced 7 r.4603 and earlier (Movable Type Advanced 7), Movable Type Advanced 6.5.2 and earlier (Movable Type Advanced 6.5), Movable Type Premium 1.26 and earlier (Movable Type Premium), and Movable Type Premium Advanced 1.26 and earlier (Movable Type Premium Advanced)) allows remote attackers to inject arbitrary web script or HTML in the block editor and the rich text editor via a specially crafted URL.

Frequently asked questions

What is CVE-2020-5528?: Cross-site scripting vulnerability in Movable Type series (Movable Type 7 r.4603 and earlier (Movable Type 7), Movable Type 6.5.2 and earlier (Movable Type 6.5), Movable Type Advanced 7 r.4603 and earlier (Movable Type Advanced 7), Movable Type Advanced 6.5.2 and earlier (Movable Type Advanced 6.5), Movable Type Premium 1.26 and earlier (Movable Type Premium), and Movable Type Premium Advanced 1.26 and earlier (Movable Type Premium Advanced)) allows remote attackers to inject arbitrary web script or HTML in the block editor and the rich text editor via a specially crafted URL.
How severe is CVE-2020-5528?: CVE-2020-5528 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-2020-5528 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (53rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-5528?: CVE-2020-5528 primarily affects Sixapart Movable Type. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2020-5528?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2020-5528 published?: CVE-2020-5528 was published on 2020-02-06 and last updated on 2026-06-17.

References

Affected products (3)

cpe:2.3:a:sixapart:movable_type:*:*:*:*:*:*:*:*
cpe:2.3:a:sixapart:movable_type:*:*:*:*:advanced:*:*:*
cpe:2.3:a:sixapart:movable_type:*:*:*:*:premium:*:*:*

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