CVE-2025-65025VulnerabilityPublished 19 Nov 2025

CVE-2025-65025: esm.sh · Path Traversal

Affects esm.shSource CVE Database V5

Not known to be exploited · CVSS 8.2 High : upgrade to 136 soon.

Data as of 26 Oct 2026, 06:26 UTC

CVSS 3.1 base score

8.2High

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.5% chance of exploitation in 30 days – higher than 46% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 136

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:N

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: Low
Integrity: High
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the impacted component.
Integrity: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 19 Nov 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-26.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade esm-dev/esm.sh to 136.

Affected software

Product	Affected	Fixed in
GitHubesm-dev/esm.sh`pkg:github/esm-dev/esm.sh`Other threats	Affected <136	Fixed in 136

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

The primary mitigation is to upgrade esm.sh to version 136 or later, where the path traversal vulnerability has been patched. Organizations should audit their use of esm.sh and ensure no legacy versions are in operation. Additionally, implement strict file system permissions on servers running esm.sh to limit the directories where files can be written, minimizing the impact of any potential exploitation. Employ monitoring and alerting for unusual file system changes, especially outside expected directories, to detect exploitation attempts early. Integrate integrity checking tools to verify the authenticity and expected structure of NPM packages before extraction. Consider sandboxing the extraction process to isolate it from critical system components. Finally, review and tighten supply chain security practices around third-party package usage to reduce the risk of malicious package introduction.

Description

esm.sh is a nobuild content delivery network(CDN) for modern web development. Prior to version 136, the esm.sh CDN service is vulnerable to path traversal during NPM package tarball extraction. An attacker can craft a malicious NPM package containing specially crafted file paths (e.g., package/../../tmp/evil.js). When esm.sh downloads and extracts this package, files may be written to arbitrary locations on the server, escaping the intended extraction directory. This issue has been patched in version 136.

Impact

For European organizations, the exploitation of CVE-2025-65025 could lead to unauthorized file writes on servers hosting esm.sh or integrated into their development pipelines. This can compromise the integrity of the development environment, potentially allowing attackers to inject malicious scripts or backdoors that could propagate into production systems. Given esm.sh's role as a CDN for modern web development, compromised servers could affect the supply chain of web applications, leading to widespread impact. The vulnerability does not directly affect confidentiality or availability but poses a high risk to integrity, which can indirectly impact confidentiality if malicious code is introduced. Organizations using esm.sh in continuous integration/continuous deployment (CI/CD) pipelines or as part of their package management infrastructure are particularly at risk. The lack of required authentication and user interaction means attackers can exploit this remotely and at scale. This could lead to reputational damage, regulatory compliance issues under GDPR if customer data is indirectly affected, and operational disruptions if malicious files cause failures or require remediation.

CWE-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') (opens in a new tab)
Base weaknessLikelihood of exploit: HighCWE Top 25 (2025): #6OWASP Top 10 A01:2025: Broken Access Control (opens in a new tab)
The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.
Implementation · Input Validation
Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.
Architecture and Design
For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks…
Implementation · Input Validation
Inputs should be decoded and canonicalized to the application's current internal representation before being validated (CWE-180). Make sure that the application does not decode the same input twice (CWE-174).
OWASP Cheat Sheets
Authorization (opens in a new tab)
OWASP ASVS 4.0.3
V12.3.1 (opens in a new tab)
Attack patterns
Path Traversal (opens in a new tab)
Using Slashes and URL Encoding Combined to Bypass Validation Logic (opens in a new tab)
Manipulating Web Input to File System Calls (opens in a new tab)
Using Escaped Slashes in Alternate Encoding (opens in a new tab)
Using Slashes in Alternate Encoding (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 26 Nov 2025, 18:56 UTC

WeaknessesCWE-22

Technical details

References

Community reviews

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