#js

In `authkit-nextjs` version 2.11.0 and below, authenticated responses do not defensively apply anti-caching headers. In environments where CDN caching is enabled, this can result in session tokens being included in cached responses and subsequently served to multiple users. Next.js applications deployed on Vercel are unaffected **unless** they manually enable CDN caching by setting cache headers on authenticated paths. ### Impact This vulnerability may lead to session caching, potentially allowing unauthorized users to obtain another user’s session token. The severity depends on deployment configuration, caching policy, and whether authenticated routes are inadvertently cached. ### Patches Patched in `authkit-nextjs` 2.11.1, which applies anti-caching headers to all responses behind authentication. ### Notes Authentication middleware should set anti-caching headers for authenticated routes as a defense in depth measure, but cannot guarantee these headers will not be overwritten els...

Martin muses on how agentic AI is bringing efficiency improvements to the business of cyber crime.

### Summary A Markdown front-matter block that contains JavaScript delimiter causes the JS engine in gray-matter library to execute arbitrary code in the Markdown to PDF converter process of **md-to-pdf** library, resulting in remote code execution. ### Details **md-to-pdf** uses the gray-matter library to parse front-matter. Gray-matter exposes a JavaScript engine that, when enabled or triggered by certain front-matter delimiters (e.g. ---js or ---javascript), will evaluate the front-matter contents as JavaScript. If user-supplied Markdown is fed to md-to-pdf and the front-matter contains malicious JS, the converter process will execute that code. ### PoC ``` const { mdToPdf } = require('md-to-pdf'); var payload = '---javascript\n((require("child_process")).execSync("calc.exe"))\n---RCE'; (async () => { await mdToPdf({ content: payload }, { dest: './output.pdf'}); })(); ``` Running the PoC on Windows launches the calculator application, demonstrating arbitrary code execution. #...

## Context A template injection vulnerability exists in LangChain's prompt template system that allows attackers to access Python object internals through template syntax. This vulnerability affects applications that accept **untrusted template strings** (not just template variables) in `ChatPromptTemplate` and related prompt template classes. Templates allow attribute access (`.`) and indexing (`[]`) but not method invocation (`()`). The combination of attribute access and indexing may enable exploitation depending on which objects are passed to templates. When template variables are simple strings (the common case), the impact is limited. However, when using `MessagesPlaceholder` with chat message objects, attackers can traverse through object attributes and dictionary lookups (e.g., `__globals__`) to reach sensitive data such as environment variables. The vulnerability specifically requires that applications accept **template strings** (the structure) from untrusted sources, not...

### Summary The public SenderContext Seal() API has a race condition which allows for the same AEAD nonce to be re-used for multiple Seal() calls. This can lead to complete loss of Confidentiality and Integrity of the produced messages. ### Details The SenderContext Seal() [implementation](https://github.com/dajiaji/hpke-js/blob/b7fd3592c7c08660c98289d67c6bb7f891af75c4/packages/core/src/senderContext.ts#L22-L34) allows for concurrent executions to trigger `computeNonce()` with the same sequence number. This results in the same nonce being used in the suite's AEAD. ### PoC This code reproduces the issue (and also checks for more things that could be wrong with the implementation). ```js import { CipherSuite, KdfId, AeadId, KemId } from "hpke-js"; const suite = new CipherSuite({ kem: KemId.DhkemP256HkdfSha256, kdf: KdfId.HkdfSha256, aead: AeadId.Aes128Gcm, }); const keypair = await suite.kem.generateKeyPair(); const skR = keypair.privateKey; const pkR = keypair.publicKey; ...

Cybersecurity researchers have warned of an actively expanding botnet dubbed Tsundere that's targeting Windows users. Active since mid-2025, the threat is designed to execute arbitrary JavaScript code retrieved from a command-and-control (C2) server, Kaspersky researcher Lisandro Ubiedo said in an analysis published today. There are currently no details on how the botnet malware is propagated;

This week has been crazy in the world of hacking and online security. From Thailand to London to the US, we've seen arrests, spies at work, and big power moves online. Hackers are getting caught. Spies are getting better at their jobs. Even simple things like browser add-ons and smart home gadgets are being used to attack people. Every day, there's a new story that shows how quickly things are

Threat actors are leveraging bogus installers masquerading as popular software to trick users into installing malware as part of a global malvertising campaign dubbed TamperedChef. The end goal of the attacks is to establish persistence and deliver JavaScript malware that facilitates remote access and control, per a new report from Acronis Threat Research Unit (TRU). The campaign, per the

### Summary 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 `${...}` expressions within CSS files, which will execute when the module is imported by victim applications. This enables Cross-Site Scripting (XSS) in browsers and Remote Code Execution (RCE) in Electron applications. **Root Cause:** The CSS module conversion logic (`router.go:1112-1119`) performs incomplete sanitization - it only checks for backticks (\`) but fails to escape template literal expressions (`${...}`), allowing arbitrary JavaScript execution when the CSS content is inserted into a template literal string. ### Details **File:** `server/router.go` **Lines:** 1112-1119 ...

### Summary The esm.sh CDN service is vulnerable to a Path Traversal (CWE-22) vulnerability 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. Uploading files containing `../` in the path is not allowed on official registries (npm, GitHub), but the `X-Npmrc` header allows specifying any arbitrary registry. By setting the registry to an attacker-controlled server via the `X-Npmrc` header, this vulnerability can be triggered. ### Details **file:** `server/npmrc.go` **line:** 552-567 ```go func extractPackageTarball(installDir string, pkgName string, tarball io.Reader) (err error) { pkgDir := path.Join(installDir, "node_modules", pkgName) tr := tar.NewReader(unziped) for { h, err := tr.Next...