ALAS2023-2026-1577

References: CVE-2026-21710  CVE-2026-21713  CVE-2026-21714  CVE-2026-21715  CVE-2026-21716  CVE-2026-21717 
FAQs regarding Amazon Linux ALAS/CVE Severity

Issue Overview:

A flaw in Node.js HTTP request handling causes an uncaught TypeError when a request is received with a header named __proto__ and the application accesses req.headersDistinct.

When this occurs, dest["__proto__"] resolves to Object.prototype rather than undefined, causing .push() to be called on a non-array. This exception is thrown synchronously inside a property getter and cannot be intercepted by error event listeners, meaning it cannot be handled without wrapping every req.headersDistinct access in a try/catch.

This vulnerability affects all Node.js HTTP servers on 20.x, 22.x, 24.x, and v25.x

NOTE: https://nodejs.org/en/blog/vulnerability/march-2026-security-releases#denial-of-service-via-__proto__-header-name-in-reqheadersdistinct-uncaught-typeerror-crashes-nodejs-process-cve-2026-21710---high (CVE-2026-21710)

A flaw in Node.js HMAC verification uses a non-constant-time comparison when validating user-provided signatures, potentially leaking timing information proportional to the number of matching bytes. Under certain threat models where high-resolution timing measurements are possible, this behavior could be exploited as a timing oracle to infer HMAC values.

Node.js already provides timing-safe comparison primitives used elsewhere in the codebase, indicating this is an oversight rather than an intentional design decision.

This vulnerability affects 20.x, 22.x, 24.x, and 25.x.

NOTE: https://nodejs.org/en/blog/vulnerability/march-2026-security-releases#timing-side-channel-in-hmac-verification-via-memcmp-in-crypto_hmaccc-leads-to-potential-mac-forgery-cve-2026-21713---medium (CVE-2026-21713)

A memory leak occurs in Node.js HTTP/2 servers when a client sends WINDOW_UPDATE frames on stream 0 (connection-level) that cause the flow control window to exceed the maximum value of 231-1. The server correctly sends a GOAWAY frame, but the Http2Session object is never cleaned up.

This vulnerability affects HTTP2 users on Node.js 20, 22, 24 and 25.

NOTE: https://nodejs.org/en/blog/vulnerability/march-2026-security-releases#memory-leak-in-nodejs-http2-server-via-window_update-on-stream-0-leads-to-resource-exhaustion-cve-2026-21714---medium (CVE-2026-21714)

A flaw in Node.js Permission Model filesystem enforcement leaves fs.realpathSync.native() without the required read permission checks, while all comparable filesystem functions correctly enforce them. As a result, code running under --permission with restricted --allow-fs-read can still use fs.realpathSync.native() to check file existence, resolve symlink targets, and enumerate filesystem paths outside of permitted directories.
This vulnerability affects 20.x, 22.x, 24.x, and 25.x processes using the Permission Model where --allow-fs-read is intentionally restricted.

NOTE: https://nodejs.org/en/blog/vulnerability/march-2026-security-releases#permission-model-bypass-in-realpathsyncnative-allows-file-existence-disclosure-cve-2026-21715---low (CVE-2026-21715)

An incomplete fix for CVE-2024-36137 leaves FileHandle.chmod() and FileHandle.chown() in the promises API without the required permission checks, while their callback-based equivalents (fs.fchmod(), fs.fchown()) were correctly patched.

As a result, code running under --permission with restricted --allow-fs-write can still use promise-based FileHandle methods to modify file permissions and ownership on already-open file descriptors, bypassing the intended write restrictions.

This vulnerability affects 20.x, 22.x, 24.x, and 25.x processes using the Permission Model where --allow-fs-write is intentionally restricted.

NOTE: https://nodejs.org/en/blog/vulnerability/march-2026-security-releases#cve-2024-36137-patch-bypass---filehandlechmodchown-cve-2026-21716---low (CVE-2026-21716)

A flaw in V8's string hashing mechanism causes integer-like strings to be hashed to their numeric value, making hash collisions trivially predictable. By crafting a request that causes many such collisions in V8's internal string table, an attacker can significantly degrade performance of the Node.js process.

The most common trigger is any endpoint that calls JSON.parse() on attacker-controlled input, as JSON parsing automatically internalizes short strings into the affected hash table.

This vulnerability affects 20.x, 22.x, 24.x, and 25.x.

NOTE: https://nodejs.org/en/blog/vulnerability/march-2026-security-releases#hashdos-in-v8-cve-2026-21717---medium (CVE-2026-21717)

Issue Correction:
Run dnf update nodejs20 --releasever 2023.11.20260413 or dnf update --advisory ALAS2023-2026-1577 --releasever 2023.11.20260413 to update your system.
More information on how to update your system can be found on this page: Amazon Linux 2023 documentation

New Packages:

aarch64:
    nodejs20-libs-debuginfo-20.20.2-1.amzn2023.0.1.aarch64
    nodejs20-debuginfo-20.20.2-1.amzn2023.0.1.aarch64
    nodejs20-devel-20.20.2-1.amzn2023.0.1.aarch64
    nodejs20-full-i18n-20.20.2-1.amzn2023.0.1.aarch64
    nodejs20-20.20.2-1.amzn2023.0.1.aarch64
    v8-11.3-devel-11.3.244.8-1.20.20.2.1.amzn2023.0.1.aarch64
    nodejs20-libs-20.20.2-1.amzn2023.0.1.aarch64
    nodejs20-npm-10.8.2-1.20.20.2.1.amzn2023.0.1.aarch64
    nodejs20-debugsource-20.20.2-1.amzn2023.0.1.aarch64

noarch:
    nodejs20-docs-20.20.2-1.amzn2023.0.1.noarch

src:
    nodejs20-20.20.2-1.amzn2023.0.1.src

x86_64:
    nodejs20-libs-debuginfo-20.20.2-1.amzn2023.0.1.x86_64
    nodejs20-full-i18n-20.20.2-1.amzn2023.0.1.x86_64
    nodejs20-20.20.2-1.amzn2023.0.1.x86_64
    nodejs20-devel-20.20.2-1.amzn2023.0.1.x86_64
    nodejs20-debuginfo-20.20.2-1.amzn2023.0.1.x86_64
    v8-11.3-devel-11.3.244.8-1.20.20.2.1.amzn2023.0.1.x86_64
    nodejs20-libs-20.20.2-1.amzn2023.0.1.x86_64
    nodejs20-npm-10.8.2-1.20.20.2.1.amzn2023.0.1.x86_64
    nodejs20-debugsource-20.20.2-1.amzn2023.0.1.x86_64