Vulnerability database
Every flaw the U.S. government’s cybersecurity agency (CISA) has confirmed attackers are using, plus the new WordPress plugin and theme bugs published each day, sorted by what they mean for a small business. We refresh it twice a day. If you see something your website or office runs, tell us.
9 results
May 28, 2026esm.sh is a no-build content delivery network (CDN) for web development.CVE-2026-44594 · Other software · esm-dev · reported by GitHubHigh 7.5
esm.sh is a no-build content delivery network (CDN) for web development. In 137 and earlier, a Local File Inclusion (LFI) vulnerability exists in the esbuild plugin's handling of the browser field in package.json. An attacker can publish an npm package that causes the server to read and return arbitrary files from the host filesystem during the build process.
- Product
- esm.sh
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
May 28, 2026esm.sh is a no-build content delivery network (CDN) for web development.CVE-2026-44593 · Other software · esm-dev · reported by GitHubHigh 8.7
esm.sh is a no-build content delivery network (CDN) for web development. In 137 and earlier, the legacy router first retrieves a response from legacyServer, parses the incoming request path, and ultimately writes the data to storage via buildStorage.Put. The router concatenates the path components without sanitizing them, producing a storage key. When this key is used, the underlying file system resolves the relative segments and writes the file to the specified path. Thus an attacker can craft a request that writes data to arbitrary locations on the server.
- Product
- esm.sh
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Feb 25, 2026esm.sh is a no-build content delivery network (CDN) for web development.CVE-2026-27730 · Other software · esm-dev · reported by GitHubHigh 7.5
esm.sh is a no-build content delivery network (CDN) for web development. Versions up to and including 137 have an SSRF vulnerability (CWE-918) in esm.sh’s `/http(s)` fetch route. The service tries to block localhost/internal targets, but the validation is based on hostname string checks and can be bypassed using DNS alias domains. This allows an external requester to make the esm.sh server fetch internal localhost services. As of time of publication, no known patched versions exist.
- Product
- esm.sh
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Feb 25, 2026esm.sh is a no-build content delivery network (CDN) for web development.CVE-2025-50180 · Other software · esm-dev · reported by GitHubHigh 8.7
esm.sh is a no-build content delivery network (CDN) for web development. In version 136, esm.sh is vulnerable to a full-response SSRF, allowing an attacker to retrieve information from internal websites through the vulnerability. Version 137 fixes the vulnerability.
- Product
- esm.sh
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Jan 18, 2026esm.sh is a no-build content delivery network (CDN) for web development.CVE-2026-23644 · Other software · esm-dev · reported by GitHubHigh 7.7
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.
- Product
- esm.sh
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Nov 19, 2025esm.sh is a nobuild content delivery network(CDN) for modern web development.CVE-2025-65026 · Other software · esm-dev · reported by GitHubMedium 6.1
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.
- Product
- esm.sh
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Nov 19, 2025esm.sh is a nobuild content delivery network(CDN) for modern web development.CVE-2025-65025 · Other software · esm-dev · reported by GitHubHigh 8.2
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.
- Product
- esm.sh
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Sep 17, 2025esm.sh is a nobuild content delivery network(CDN) for modern web development.CVE-2025-59342 · Other software · esm-dev · reported by GitHubMedium 5.5
esm.sh is a nobuild content delivery network(CDN) for modern web development. In 136 and earlier, a path-traversal flaw in the handling of the X-Zone-Id HTTP header allows an attacker to cause the application to write files outside the intended storage location. The header value is used to build a filesystem path but is not properly canonicalized or restricted to the application’s storage base directory. As a result, supplying ../ sequences in X-Zone-Id causes files to be written to arbitrary directories. Version 136.1 contains a patch.
- Product
- esm.sh
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Sep 17, 2025esm.sh is a nobuild content delivery network(CDN) for modern web development.CVE-2025-59341 · Other software · esm-dev · reported by GitHubHigh 7.7
esm.sh is a nobuild content delivery network(CDN) for modern web development. In 136 and earlier, 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).
- Product
- esm.sh
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Where this comes from: the exploited list is CISA’s Known Exploited Vulnerabilities catalog. Everything else is the whole National Vulnerability Database, where each record is published by the team that found the bug (Wordfence, Patchstack, WPScan, the vendors themselves and others); we show who. Exploit odds are FIRST’s EPSS, updated daily. Titles and categories are ours, so check the linked record before acting on a detail. For a write-up of the big ones, see our advisories. Every vendor, and every WordPress plugin and theme with a recorded flaw, also has its own page. All of it is free to reuse as JSON, CSV or RSS.
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