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TI-2026-45186 Aliases CVE-2026-63386

js-toml: Uncontrolled recursion in `load()` causes `RangeError` (stack exhaustion) on deeply nested input

Priority MEDIUM 63CWE-674Published · Updated

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

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00361 30th percentileScored 2026-11-07
Fix Fixed js-toml (sunnyadn): 1.1.3

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

VendorProductAffected versionsFixed inStatusSource
sunnyadnjs-tomlbefore 1.1.31.1.3Patch availableCNA
  • js-toml Vendorsunnyadn Affected before 1.1.3 Fixed in 1.1.3 Patch available CNA

Remediation

  • Fix · CNA js-toml (sunnyadn) Fixed in 1.1.3

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-63386

References

  • 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