high CVSS 7.5

CVE-2025-59465·Node.js vulnerability

A malformed `HTTP/2 HEADERS` frame with oversized, invalid `HPACK` data can cause Node.js to crash by triggering an unhandled `TLSSocket` error `ECONNRESET`. Instead of safely closing the connection, the process crashes, enabling a remote denial of service. This primarily affects applications that do not attach explicit error handlers to secure sockets, for example: ``` server.on('secureConnection', socket => { socket.on('error', err => { console.log(err) }) }) ```

Severity
high
Software
Node.js
Fixed in
25.3.0
Published
2026-01-20

Affected versions

From: 25.0.0

Until: 25.3.0

Fixed in: 25.3.0

How to fix this CVE

Update Node.js to version 25.3.0 or later to patch a critical HTTP/2 vulnerability that allows remote attackers to crash the process via malformed HEADERS frames. Applications running Node.js 25.0.0–25.3.0 should prioritize this update, especially those serving HTTP/2 traffic without explicit socket error handlers. After patching, verify the fix by restarting services and monitoring for connection reset errors in logs.

sudo dnf update nodejs

Defensia detects this vulnerability

What an exploitation attempt looks like

Sample log line indicative of exploitation attempts:

Malformed HTTP/2 HEADERS frame with oversized HPACK encoding followed by ECONNRESET; log pattern: "TLSSocket error ECONNRESET" or "Error: socket hang up" appearing without explicit socket.on('error') handler in application code

WAF mitigation (if patching is not yet possible)

Add this rule to your WAF to block exploitation attempts while you schedule the patch. 

Implement HTTP/2 frame validation at the ingress layer to reject HEADERS frames with invalid or oversized HPACK data before they reach the Node.js process; enforce maximum frame size limits and validate HPACK compression ratios

How to check if you are affected

  1. Check installed Node.js version: node --version or nodejs --version
  2. Confirm if your application handles HTTP/2 connections: grep -r 'http2\|secureConnection' /path/to/app --include='*.js'
  3. Search application logs for ECONNRESET errors paired with TLSSocket: grep -i 'ECONNRESET\|TLSSocket' /var/log/app.log /var/log/nodejs.log 2>/dev/null
  4. Verify the patch by checking the updated version: node --version and confirm output shows 25.3.0 or higher

FAQ

What is CVE-2025-59465?

This is a denial-of-service vulnerability in Node.js where attackers send specially crafted HTTP/2 frames with invalid HPACK data to trigger an unhandled TLSSocket error that crashes the entire process, rather than gracefully closing the connection.

Is CVE-2025-59465 being actively exploited?

No, this vulnerability is not currently listed in the CISA KEV catalog and has no public exploits available, though the network-accessible nature of the flaw makes it a realistic target for opportunistic attackers.

What versions of Node.js are affected by CVE-2025-59465?

Versions 25.0.0 through 25.3.0 are vulnerable. Version 25.3.0 and later include the fix.

How do I check if my server is vulnerable to CVE-2025-59465?

Run `node --version` and confirm the output is between 25.0.0 and 25.3.0. If so, your server requires the patch. Additionally, check if your application uses HTTP/2 without explicit error handlers on secure sockets.

Does Defensia detect CVE-2025-59465?

Yes — Defensia's CVE advisory scanner compares installed package versions against the NVD database. If Node.js is installed on a monitored server, CVE-2025-59465 will appear in your dashboard with remediation steps.

Related Node.js CVEs

CVE-2026-21636CVSS 10A flaw in Node.js's permission model allows Unix Domain Socket (UDS) connections to bypass network restrictions when `--permission` is enabled. Even without `--allow-net`, attacker-controlled inputs (such as URLs or socketPath options) can connect to arbitrary local sockets via net, tls, or undici/fetch. This breaks the intended security boundary of the permission model and enables access to privileged local services, potentially leading to privilege escalation, data exposure, or local code execution. * The issue affects users of the Node.js permission model on version v25. In the moment of this vulnerability, network permissions (`--allow-net`) are still in the experimental phase.
CVE-2025-55130CVSS 9.1A flaw in Node.js’s Permissions model allows attackers to bypass `--allow-fs-read` and `--allow-fs-write` restrictions using crafted relative symlink paths. By chaining directories and symlinks, a script granted access only to the current directory can escape the allowed path and read sensitive files. This breaks the expected isolation guarantees and enables arbitrary file read/write, leading to potential system compromise. This vulnerability affects users of the permission model on Node.js v20, v22, v24, and v25.
CVE-2025-59464CVSS 7.5A memory leak in Node.js’s OpenSSL integration occurs when converting `X.509` certificate fields to UTF-8 without freeing the allocated buffer. When applications call `socket.getPeerCertificate(true)`, each certificate field leaks memory, allowing remote clients to trigger steady memory growth through repeated TLS connections. Over time this can lead to resource exhaustion and denial of service.
CVE-2025-59466CVSS 7.5We have identified a bug in Node.js error handling where "Maximum call stack size exceeded" errors become uncatchable when `async_hooks.createHook()` is enabled. Instead of reaching `process.on('uncaughtException')`, the process terminates, making the crash unrecoverable. Applications that rely on `AsyncLocalStorage` (v22, v20) or `async_hooks.createHook()` (v24, v22, v20) become vulnerable to denial-of-service crashes triggered by deep recursion under specific conditions.
CVE-2026-21637CVSS 7.5A flaw in Node.js TLS error handling allows remote attackers to crash or exhaust resources of a TLS server when `pskCallback` or `ALPNCallback` are in use. Synchronous exceptions thrown during these callbacks bypass standard TLS error handling paths (tlsClientError and error), causing either immediate process termination or silent file descriptor leaks that eventually lead to denial of service. Because these callbacks process attacker-controlled input during the TLS handshake, a remote client can repeatedly trigger the issue. This vulnerability affects TLS servers using PSK or ALPN callbacks across Node.js versions where these callbacks throw without being safely wrapped.

References

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