How severe is CVE-2020-5553?

CVE-2020-5553 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2020-5553 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (81st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-5553?

CVE-2020-5553 affects Mailform. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2020-5553?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2020-5553 published?

CVE-2020-5553 was published on 2020-03-25 and last updated on 2026-06-17.

CVE-2020-5553

CVE-2020-5553 is a critical-severity vulnerability in Mailform with a CVSS 3.x base score of 9.8. 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-94.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 10.0
EPSS exploit prediction: 2% (81st percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-94
Affected product: Mailform
Published: 2020-03-25
Last modified: 2026-06-17

Description

mailform version 1.04 allows remote attackers to execute arbitrary PHP code via unspecified vectors.

Frequently asked questions

What is CVE-2020-5553?: mailform version 1.04 allows remote attackers to execute arbitrary PHP code via unspecified vectors.
How severe is CVE-2020-5553?: CVE-2020-5553 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2020-5553 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (81st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-5553?: CVE-2020-5553 affects Mailform. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2020-5553?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2020-5553 published?: CVE-2020-5553 was published on 2020-03-25 and last updated on 2026-06-17.

References

https://jvn.jp/en/jp/JVN77634892/index.html

Affected products (1)

cpe:2.3:a:mailform:mailform:1.04:*:*:*:*:*:*:*

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