GHSA-48c2-rrv3-qjmp · Severity: medium · Ecosystem: npm — yaml is vulnerable to Stack Overflow via deeply nested YAML collections
`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.
Conclusion & alert: CVE-2026-33532 is rated Exploit Available (50/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.02%). Core evidence: 1 public exploit reference(s) are indexed (Exploit-DB). Mandatory action: Public exploits are available—assess exposure, apply mitigations, and prioritize patching.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
| EDB-ID | Source | Kind | Published | Link |
|---|---|---|---|---|
| — | nvd_ref | exploit_tag | Exploit-DB ↗ |
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2026-05-22 | 0.05% | 0.02% | -0.03% |
| 2 | 2026-04-01 | 0.04% | 0.05% | +0.01% |
| 3 | 2026-03-27 | — | 0.04% | — |
Full EPSS history (3 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 4.3 | 3.1 | MEDIUM |
|
2.8 | 1.4 | [email protected] |
GHSA-48c2-rrv3-qjmp · Severity: medium · Ecosystem: npm — yaml is vulnerable to Stack Overflow via deeply nested YAML collections
| vendor | priority | summary | link |
|---|---|---|---|
debian
|
not yet assigned | CVE-2026-33532 not yet assigned priority: Debian including 1 source packages (node-yaml), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): open 3, resolved 2. | https://security-tracker.debian.org/tracker/CVE-2026-33532 |
redhat
|
medium | — | https://access.redhat.com/security/cve/CVE-2026-33532 |
suse
|
medium | CVE-2026-33532 severity moderate: SUSE including 3 source package names (pgadmin4, pgadmin4-doc, pgadmin4-web), 6 product×package rows across 2 product lines (SUSE Linux Enterprise Server 15 SP1-LTSS, SUSE Linux Enterprise Server 15 SP2-LTSS): Known Not Affected 6. | https://www.suse.com/security/cve/CVE-2026-33532/ |
ubuntu
|
medium | CVE-2026-33532 medium priority: Ubuntu including 1 source packages (node-yaml), 4 status rows across 4 suites (jammy, noble, questing, upstream): needs-triage 3, released 1. | https://ubuntu.com/security/CVE-2026-33532 |
| URL | Tags |
|---|---|
| https://github.com/eemeli/yaml/commit/1e84ebbea7ec35011a4c61bbb820a529ee4f359b | Patch |
| https://github.com/eemeli/yaml/releases/tag/v1.10.3 | Product |
| https://github.com/eemeli/yaml/releases/tag/v2.8.3 | Release Notes |
| https://github.com/eemeli/yaml/security/advisories/GHSA-48c2-rrv3-qjmp | Exploit Vendor Advisory |