critical CVSS 9

CVE-2026-48933·Node.js vulnerability

A flaw in Node.js WebCrypto implementation can crash the process if the input of `subtle.encrypt()` is a multiple of 2GiB. This vulnerability affects all supported release lines: **Node.js 22**, **Node.js 24**, and **Node.js 26**.

Severity
critical
Software
Node.js
Fixed in
18.20.4+dfsg-1~deb12u3
Published

Affected versions

Until: 18.20.4+dfsg-1~deb12u3

Fixed in: 18.20.4+dfsg-1~deb12u3

How to fix this CVE

Update Node.js to version 18.20.4+dfsg-1~deb12u3 or later to patch a WebCrypto denial-of-service flaw that can terminate the process when processing large encrypted payloads. Immediately apply this update to all Node.js deployments, particularly those running cryptographic operations at scale. Test the patched version in a staging environment before rolling out to production.

sudo dnf update nodejs

Defensia detects this vulnerability

How to check if you are affected

  1. Check your Node.js version: node --version and compare against 18.20.4+dfsg-1~deb12u3
  2. Verify if your application uses WebCrypto's subtle.encrypt() method: grep -r 'subtle.encrypt' /path/to/your/app/
  3. Monitor system logs for unexpected Node.js process crashes: journalctl -u nodejs -n 100 --no-pager
  4. Confirm the patch was applied by re-running node --version and confirming it matches or exceeds 18.20.4+dfsg-1~deb12u3

FAQ

What is CVE-2026-48933?

CVE-2026-48933 is a critical denial-of-service vulnerability in Node.js WebCrypto where the subtle.encrypt() function crashes the entire process when handling input payloads that are exact multiples of 2 gigabytes. This flaw affects all supported Node.js release lines.

Is CVE-2026-48933 being actively exploited?

No, this vulnerability is not currently listed on CISA's Known Exploited Vulnerabilities catalog, and no public exploits are available.

What versions of Node.js are affected by CVE-2026-48933?

Node.js versions up to and including 18.20.4+dfsg-1~deb12u3 are affected. The vulnerability impacts all supported release lines including Node.js 22, 24, and 26.

How do I check if my server is vulnerable to CVE-2026-48933?

Run node --version and compare the output to 18.20.4+dfsg-1~deb12u3. If your version is older, your system is vulnerable. Additionally, check dpkg -l | grep nodejs (Debian/Ubuntu) or rpm -qa | grep nodejs (RHEL/CentOS) to confirm the exact installed version.

Does Defensia detect CVE-2026-48933?

Yes — Defensia's CVE advisory scanner compares installed package versions against the NVD database. If Node.js is installed on a monitored server, CVE-2026-48933 will appear in your dashboard with remediation steps.

Related Node.js CVEs

CVE-2026-48930CVSS 10A flaw in Node.js TLS hostname handling can cause Embedded-nul hostnames can lead to silent authority rebinding due to c-string truncation in resolver bindings. This vulnerability affects all supported release lines: **Node.js 22**, **Node.js 24**, and **Node.js 26**.
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-2026-48619CVSS 9A flaw in Node.js HTTP/2 client allows a server to send an unlimited number of ORIGIN frames, which could lead to an Out of Memory error on the client. This vulnerability affects all supported release lines: **Node.js 22**, **Node.js 24**, and **Node.js 26**.
CVE-2026-48937CVSS 9A flaw in Node.js HTTP/2 server API can cause servers to keep accepting data even after sending a `GOAWAY` frame. This vulnerability affects two supported release lines: **Node.js 22** and **Node.js 24**.

References

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