CVE-2021-32820

CVE-2021-32820 is a high-severity vulnerability in Express Handlebars Project Express Handlebars with a CVSS 3.x base score of 8.6. Its EPSS exploit-prediction score of 18% places it in the 97th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-94.

Key facts

Description

Express-handlebars is a Handlebars view engine for Express. Express-handlebars mixes pure template data with engine configuration options through the Express render API. More specifically, the layout parameter may trigger file disclosure vulnerabilities in downstream applications. This potential vulnerability is somewhat restricted in that only files with existing extentions (i.e. file.extension) can be included, files that lack an extension will have .handlebars appended to them. For complete details refer to the referenced GHSL-2021-018 report. Notes in documentation have been added to help users avoid this potential information exposure vulnerability.

Frequently asked questions

What is CVE-2021-32820?
Express-handlebars is a Handlebars view engine for Express. Express-handlebars mixes pure template data with engine configuration options through the Express render API. More specifically, the layout parameter may trigger file disclosure vulnerabilities in downstream applications. This potential vulnerability is somewhat restricted in that only files with existing extentions (i.e. file.extension) can be included, files that lack an extension will have .handlebars appended to them. For complete details refer to the referenced GHSL-2021-018 report. Notes in documentation have been added to help users avoid this potential information exposure vulnerability.
How severe is CVE-2021-32820?
CVE-2021-32820 has a CVSS 3.x base score of 8.6, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2021-32820 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 18% (97th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-32820?
CVE-2021-32820 affects Express Handlebars Project Express Handlebars. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-32820?
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-2021-32820 published?
CVE-2021-32820 was published on 2021-05-14 and last updated on 2026-06-17.

References

Affected products (1)

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