What is CVE-2020-5574?

CVE-2020-5574 is a medium-severity vulnerability in Sixapart Movable Type, classified under Improper Neutralization of Special Elements in Output Used by a Downstream Component (Injection). CVSS score: 5.3/10. Published 2020-05-14.

How severe is CVE-2020-5574?

Medium severity. CVSS v3 base score is 5.3 out of 10.

Vulnerability in Sixapart Movable Type

CVE-2020-5574

HTML attribute value injection vulnerability in Movable Type series (Movable Type 7 r.4606 (7.2.1) and earlier (Movable Type 7), Movable Type Advanced 7 r.4606 (7.2.1) and earlier (Movable Type Advanced 7), Movable Type for AWS 7 r.4606 (7.2.1) and earlier (Movable Type for AWS 7), Movable Type 6.5.3 and earlier (Movable Type 6.5), Movable Type Advanced 6.5.3 and earlier (Movable Type Advanced 6.5), Movable Type 6.3.11 and earlier (Movable Type 6.3), Movable Type Advanced 6.3.11 and earlier (Movable Type 6.3), Movable Type Premium 1.29 and earlier, and Movable Type Premium Advanced 1.29 and earlier) allows remote attackers to inject arbitrary HTML attribute value via unspecified vectors.

Published 2020-05-14 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N.

EPSS exploit prediction

EPSS: 0.012 (67.1th percentile), scored 2026-09-29.

Low probability of exploitation in the next 30 days, but still tracked. 67th percentile — 67.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.012 · newest: 0.012 · change: 0.000

Affected products

Sixapart Movable Type
Six Apart Ltd. Movable Type — versions Movable Type 7 r.4606 (7.2.1) and earlier (Movable Type 7), Movable Type Advanced 7 r.4606 (7.2.1) and earlier (Movable Type Advanced 7), Movable Type for AWS 7 r.4606 (7.2.1) and earlier (Movable Type for AWS 7), Movable Type 6.5.3 and earlier (Movable Type 6.5), Movable Type Advanced 6.5.3 and earlier (Movable Type Advanced 6.5), Movable Type 6.3.11 and earlier (Movable Type 6.3), Movable Type Advanced 6.3.11 and earlier (Movable Type 6.3), Movable Type Premium 1.29 and earlier, and Movable Type Premium Advanced 1.29 and earlier

Weakness classification (CWE)

CWE-74 — Improper Neutralization of Special Elements in Output Used by a Downstream Component (Injection)

References

movabletype.org/news/2020/05/mt-730-660-6312-released.html (Release Notes, Vendor Advisory)
jvn.jp/en/jp/JVN28806943/index.html (VDB Entry, Third Party Advisory)

Frequently asked questions

What is CVE-2020-5574?: CVE-2020-5574 is a medium-severity vulnerability in Sixapart Movable Type, classified under Improper Neutralization of Special Elements in Output Used by a Downstream Component (Injection). CVSS score: 5.3/10. Published 2020-05-14.
How severe is CVE-2020-5574?: Medium severity. CVSS v3 base score is 5.3 out of 10.