Category

Redos

Security vulnerabilities and automated fixes for redos issues

10 posts found

high7 min

How Regular Expression Denial of Service (ReDoS) Happens in Node.js trim-newlines and How to Fix It

CVE-2021-33623 exposed a Regular Expression Denial of Service (ReDoS) vulnerability in the npm package `trim-newlines` versions 1.0.0 and earlier. The vulnerable `.end()` method used an inefficient regex pattern that could cause severe performance degradation when processing malicious input. Upgrading to version 4.0.1 patches the regex implementation and eliminates the attack surface.

#injection#redos#regex+4 more
A
anupamme
Sep 10, 2026
high8 min

How ReDoS via Unbounded Brace Expansion happens in Node.js and how to fix it

CVE-2024-4068 is a high-severity Regular Expression Denial of Service (ReDoS) vulnerability in the `braces` npm package (versions prior to 3.0.3) that allows an attacker to trigger catastrophic CPU consumption by supplying a crafted brace-expansion string with no character limit. The fix upgrades `braces` from 3.0.2 to 3.0.3 and its internal dependency `fill-range` from 7.0.1 to 7.1.1, both of which enforce limits on the size of input they will process. This patch was applied via a Yarn resoluti

#security#nodejs#javascript+2 more
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anupamme
Aug 26, 2026
medium7 min

How Denial of Service via Catastrophic Backtracking happens in Node.js and how to fix it

CVE-2026-4867 is a Regular Expression Denial of Service (ReDoS) vulnerability in the `path-to-regexp` package (versions prior to 0.1.13) that allows an attacker to craft malformed URL parameters that cause catastrophic backtracking in the regex engine, effectively hanging the Node.js event loop. The fix upgrades `path-to-regexp` from 0.1.12 to 0.1.13 and pins the version via an `overrides` field in `package.json` to ensure the patched version is used throughout the entire dependency tree. Any Ex

#security#nodejs#redos+2 more
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anupamme
Aug 26, 2026
high7 min

How ReDoS happens in Node.js path-to-regexp and how to fix it

CVE-2024-52798 is a Regular Expression Denial of Service (ReDoS) vulnerability in the `path-to-regexp` package's 0.1.x branch, which remains unpatched in that legacy line. Because `path-to-regexp` is a transitive dependency pulled in by `websocket-driver` and many other popular Node.js packages, any application that processes attacker-controlled URL paths through an affected version is at risk of catastrophic backtracking that can freeze the event loop. Upgrading `websocket-driver` to 0.7.5 — an

#security#redos#nodejs+2 more
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anupamme
Aug 25, 2026
high7 min

How Regular Expression Denial of Service happens in JavaScript and how to fix it

CVE-2026-33671 is a Regular Expression Denial of Service (ReDoS) vulnerability in the picomatch glob-matching library, triggered by specially crafted extglob patterns that cause catastrophic regex backtracking. The fix upgrades picomatch to version 4.0.4 (with overrides pinning all transitive copies) in the client's dependency tree, eliminating the vulnerable regex evaluation path. Left unpatched, any code path that passes user-influenced glob patterns to picomatch could be weaponized to stall a

#redos#javascript#nodejs+4 more
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anupamme
Aug 23, 2026
high7 min

How Denial of Service via Regular Expression Happens in Node.js Dependencies and How to Fix It

A high-severity denial of service vulnerability in the `path-to-regexp` package (CVE-2026-4926) could allow attackers to craft malicious regular expressions that consume excessive CPU resources. The fix upgrades from version 8.2.0 to 8.4.0, which hardens regex handling and prevents ReDoS (Regular Expression Denial of Service) attacks in Express applications.

#security#redos#nodejs+4 more
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anupamme
Aug 21, 2026
high5 min

How API key exposure and ReDoS happens in Node.js and how to fix it

A critical vulnerability in `roll/openai.js` could expose OpenAI API keys to client-side JavaScript bundles, allowing attackers to extract secrets from browser developer tools. Additionally, a Regular Expression Denial of Service (ReDoS) pattern in the `generateErrorMessage()` method could crash the process. Both issues were fixed with targeted, minimal code changes.

#security#nodejs#api-key-exposure+4 more
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anupamme
Aug 1, 2026
high5 min

How ReDoS happens in Node.js MCP SDK and how to fix it

A Regular Expression Denial of Service (ReDoS) vulnerability was discovered in Anthropic's Model Context Protocol (MCP) TypeScript SDK version 1.24.0. This high-severity flaw (CVE-2026-0621) could allow attackers to craft malicious input that causes catastrophic regex backtracking, freezing the Node.js event loop. The fix involves upgrading to @modelcontextprotocol/sdk version 1.25.2, which patches the vulnerable regex patterns.

#security#redos#nodejs+4 more
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anupamme
Jul 25, 2026
high9 min

How Regular Expression Denial of Service happens in Node.js picomatch extglob patterns and how to fix it

A Regular Expression Denial of Service (ReDoS) vulnerability in picomatch versions prior to 2.3.2, 3.0.2, and 4.0.4 allowed attackers to craft malicious extglob patterns that triggered catastrophic backtracking in the regex engine, potentially freezing Node.js applications. The fix, tracked as CVE-2026-33671, involved upgrading picomatch to patched versions and pinning the dependency explicitly in `package.json` to ensure the safe version is resolved across the dependency tree.

#security#nodejs#regex+5 more
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orbisai0security
Jul 9, 2026
high8 min

ReDoS in Nushell's TUI: When Search Input Freezes Your Terminal

A high-severity Regular Expression Denial of Service (ReDoS) vulnerability was discovered and patched in Nushell's interactive TUI explorer, where unvalidated user keystrokes could be passed directly into regex compilation, allowing adversarial inputs to consume 100% CPU and freeze the interface. This fix adds proper input validation and length limits to the search input handler, preventing catastrophic backtracking attacks. Understanding this vulnerability is essential for any developer buildin

#security#redos#regex+4 more
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orbisai0security
May 20, 2026