How severe is CVE-2021-37626?

CVE-2021-37626 has a CVSS 3.x base score of 7.2, rated high severity. It is exploitable over network with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-37626 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (66th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-37626?

CVE-2021-37626 primarily affects Contao. In total, 10 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-37626?

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-2021-37626 published?

CVE-2021-37626 was published on 2021-08-11 and last updated on 2026-06-17.

CVE-2021-37626

CVE-2021-37626 is a high-severity vulnerability in Contao with a CVSS 3.x base score of 7.2. 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: High (CVSS 3.x base score 7.2)
CVSS v2: 6.5
EPSS exploit prediction: 1% (66th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-94
Affected product: Contao
Published: 2021-08-11
Last modified: 2026-06-17

Description

Contao is an open source CMS that allows you to create websites and scalable web applications. In affected versions it is possible to load PHP files by entering insert tags in the Contao back end. Installations are only affected if they have untrusted back end users who have the rights to modify fields that are shown in the front end. Update to Contao 4.4.56, 4.9.18 or 4.11.7 to resolve. If you cannot update then disable the login for untrusted back end users.

Frequently asked questions

What is CVE-2021-37626?: Contao is an open source CMS that allows you to create websites and scalable web applications. In affected versions it is possible to load PHP files by entering insert tags in the Contao back end. Installations are only affected if they have untrusted back end users who have the rights to modify fields that are shown in the front end. Update to Contao 4.4.56, 4.9.18 or 4.11.7 to resolve. If you cannot update then disable the login for untrusted back end users.
How severe is CVE-2021-37626?: CVE-2021-37626 has a CVSS 3.x base score of 7.2, rated high severity. It is exploitable over network with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-37626 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (66th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-37626?: CVE-2021-37626 primarily affects Contao. In total, 10 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-37626?: 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-2021-37626 published?: CVE-2021-37626 was published on 2021-08-11 and last updated on 2026-06-17.

References

Affected products (10)

cpe:2.3:a:contao:contao:*:*:*:*:*:*:*:*
cpe:2.3:a:contao:contao:4.0.0:*:*:*:*:*:*:*
cpe:2.3:a:contao:contao:4.1.0:*:*:*:*:*:*:*
cpe:2.3:a:contao:contao:4.2.0:*:*:*:*:*:*:*
cpe:2.3:a:contao:contao:4.3.0:*:*:*:*:*:*:*
cpe:2.3:a:contao:contao:4.5.0:*:*:*:*:*:*:*
cpe:2.3:a:contao:contao:4.6.0:*:*:*:*:*:*:*
cpe:2.3:a:contao:contao:4.7.0:*:*:*:*:*:*:*
cpe:2.3:a:contao:contao:4.8.0:*:*:*:*:*:*:*
cpe:2.3:a:contao:contao:4.10.0:*:*:*:*:*:*:*

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