How severe is CVE-2026-23644?

CVE-2026-23644 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability none.

Is CVE-2026-23644 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (38th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-23644?

CVE-2026-23644 affects Esm Esm.sh. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-23644?

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.

Does CVE-2026-23644 have an EU (EUVD) identifier?

Yes. CVE-2026-23644 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-3402.

When was CVE-2026-23644 published?

CVE-2026-23644 was published on 2026-01-18 and last updated on 2026-06-17.

CVE-2026-23644

CVE-2026-23644 is a high-severity vulnerability in Esm Esm.sh with a CVSS 3.x base score of 7.5. 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-22.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v4: 7.7
EPSS exploit prediction: 0% (38th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-3402
Weakness: CWE-22
Affected product: Esm Esm.sh
Published: 2026-01-18
Last modified: 2026-06-17

Description

esm.sh is a no-build content delivery network (CDN) for web development. Prior to Go pseeudoversion 0.0.0-20260116051925-c62ab83c589e, the software has a path traversal vulnerability due to an incomplete fix. `path.Clean` normalizes a path but does not prevent absolute paths in a malicious tar file. Commit https://github.com/esm-dev/esm.sh/commit/9d77b88c320733ff6689d938d85d246a3af9af16, corresponding to pseudoversion 0.0.0-20260116051925-c62ab83c589e, fixes this issue.

Frequently asked questions

What is CVE-2026-23644?: esm.sh is a no-build content delivery network (CDN) for web development. Prior to Go pseeudoversion 0.0.0-20260116051925-c62ab83c589e, the software has a path traversal vulnerability due to an incomplete fix. `path.Clean` normalizes a path but does not prevent absolute paths in a malicious tar file. Commit https://github.com/esm-dev/esm.sh/commit/9d77b88c320733ff6689d938d85d246a3af9af16, corresponding to pseudoversion 0.0.0-20260116051925-c62ab83c589e, fixes this issue.
How severe is CVE-2026-23644?: CVE-2026-23644 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability none.
Is CVE-2026-23644 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (38th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-23644?: CVE-2026-23644 affects Esm Esm.sh. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-23644?: 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.
Does CVE-2026-23644 have an EU (EUVD) identifier?: Yes. CVE-2026-23644 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-3402.
When was CVE-2026-23644 published?: CVE-2026-23644 was published on 2026-01-18 and last updated on 2026-06-17.

References

Affected products (1)

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

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