# CVE-2026-33532: node-yaml: `yaml` is a YAML parser and serialiser for JavaScript

CVE-2026-33532 is fixed in 2 products on 1 platform, first by DEBIAN-CVE-2026-33532, released March 26, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-33532
- Priority: Routine
- CVSS: 4.3 (medium)
- EPSS: 0.0049
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Mar 26, 2026

## Description

`yaml` is a YAML parser and serialiser for JavaScript. Parsing a YAML document with a version of `yaml` on the 1.x branch prior to 1.10.3 or on the 2.x branch prior to 2.8.3 may throw a RangeError due to a stack overflow. The node resolution/composition phase uses recursive function calls without a depth bound. An attacker who can supply YAML for parsing can trigger a `RangeError: Maximum call stack size exceeded` with a small payload (~2–10 KB). The `RangeError` is not a `YAMLParseError`, so applications that only catch YAML-specific errors will encounter an unexpected exception type. Depending on the host application's exception handling, this can fail requests or terminate the Node.js process. Flow sequences allow deep nesting with minimal bytes (2 bytes per level: one `[` and one `]`). On the default Node.js stack, approximately 1,000–5,000 levels of nesting (2–10 KB input) exhaust the call stack. The exact threshold is environment-dependent (Node.js version, stack size, call stack depth at invocation). Note: the library's `Parser` (CST phase) uses a stack-based iterative approach and is not affected. Only the compose/resolve phase uses actual call-stack recursion. All three public parsing APIs are affected: `YAML.parse()`, `YAML.parseDocument()`, and `YAML.parseAllDocuments()`. Versions 1.10.3 and 2.8.3 contain a patch.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | alloy opensuse-leap 16.0 | 1.17.0-160000.1.1 | [OPENSUSE-SU-2026:21251-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21251-1.md) | Jul 7, 2026 |
| Linux | alloy sles 15.7 | 1.17.1-150700.15.23.1 | [SUSE-SU-2026:2824-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-2824-1.md) | Jul 9, 2026 |
| Linux | alloy sles 16.0 | 1.17.0-160000.1.1 | [SUSE-SU-2026:22575-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-22575-1.md) | Jul 7, 2026 |
| Linux | node-yaml Debian 14 | 2.8.3+~cs0.4.0-1 | [DEBIAN-CVE-2026-33532](https://patchblox.com/security/data/fix/linux/debian-cve-2026-33532.md) | Mar 26, 2026 |

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Data as of 2026-11-08T13:06:02Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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