js-toml: Uncontrolled recursion in `load()` causes `RangeError` (stack exhaustion) on deeply nested input
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · Low
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-674.
Summary
js-toml is a TOML parser for JavaScript. Prior to 1.1.3, load() does not bound nesting or dotted-key depth in the recursive parser at src/load/parser.ts or the interpreter at src/load/interpreter.ts, so deeply nested arrays, deeply nested inline tables, or long dotted keys can exhaust the V8 call stack and throw a raw RangeError instead of the documented SyntaxParseError. Applications that parse attacker-controlled TOML and handle only SyntaxParseError can rethrow the unexpected exception, which can terminate a worker or process and cause denial of service. The exception is synchronous and catchable by consumers that handle all exceptions, and the issue does not affect confidentiality or integrity. This issue is fixed in version 1.1.3.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
- Fix · CNA js-toml (sunnyadn) Fixed in 1.1.3
Timeline
- 2026-10-02 Threatist record created from CVE-2026-63386
References
More sunnyadn vulnerabilities
- TI-2025-34557 js-toml is vulnerable to Prototype Pollution CVSS 4.0HIGH 7.9
- TI-2026-36479 CPU exhaustion via O(n^2) BigInt construction on radix-prefixed integer literals CVSS 3.1HIGH 7.5
- TI-2026-36854 js-toml has silent type confusion via falsy-primitive duplicate-key bypass CVSS 3.1MEDIUM 5.3
Sources
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences