How severe is CVE-2025-65026?

CVE-2025-65026 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-2025-65026 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (36th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2025-65026?

CVE-2025-65026 affects Esm Esm.sh. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2025-65026?

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

Does CVE-2025-65026 have an EU (EUVD) identifier?

Yes. CVE-2025-65026 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-198180.

When was CVE-2025-65026 published?

CVE-2025-65026 was published on 2025-11-19 and last updated on 2026-06-17.

CVE-2025-65026

CVE-2025-65026 is a medium-severity vulnerability in Esm Esm.sh 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)
EPSS exploit prediction: 0% (36th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-198180
Weakness: CWE-79
Affected product: Esm Esm.sh
Published: 2025-11-19
Last modified: 2026-06-17

Description

esm.sh is a nobuild content delivery network(CDN) for modern web development. Prior to version 136, The esm.sh CDN service contains a Template Literal Injection vulnerability (CWE-94) in its CSS-to-JavaScript module conversion feature. When a CSS file is requested with the ?module query parameter, esm.sh converts it to a JavaScript module by embedding the CSS content directly into a template literal without proper sanitization. An attacker can inject malicious JavaScript code using ${...} expressions within CSS files, which will execute when the module is imported by victim applications. This enables Cross-Site Scripting (XSS) in browsers and Remote Code Execution (RCE) in Electron applications. This issue has been patched in version 136.

Frequently asked questions

What is CVE-2025-65026?: esm.sh is a nobuild content delivery network(CDN) for modern web development. Prior to version 136, The esm.sh CDN service contains a Template Literal Injection vulnerability (CWE-94) in its CSS-to-JavaScript module conversion feature. When a CSS file is requested with the ?module query parameter, esm.sh converts it to a JavaScript module by embedding the CSS content directly into a template literal without proper sanitization. An attacker can inject malicious JavaScript code using ${...} expressions within CSS files, which will execute when the module is imported by victim applications. This enables Cross-Site Scripting (XSS) in browsers and Remote Code Execution (RCE) in Electron applications. This issue has been patched in version 136.
How severe is CVE-2025-65026?: CVE-2025-65026 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-2025-65026 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (36th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-65026?: CVE-2025-65026 affects Esm Esm.sh. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2025-65026?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2025-65026 have an EU (EUVD) identifier?: Yes. CVE-2025-65026 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-198180.
When was CVE-2025-65026 published?: CVE-2025-65026 was published on 2025-11-19 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:esm:esm.sh:*:*:*:*:*:*:*:*

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