CVE-2026-49293
Published:June 19, 2026
Updated:June 29, 2026
js-toml is a TOML parser for JavaScript, fully compliant with the TOML 1.0.0 Spec. Versions up to and including 1.1.0 parse hexadecimal / octal / binary integer literals via a hand-written "parseBigInt" loop that multiplies a "BigInt" accumulator by the radix once per input digit. Each iteration performs a "BigInt * BigInt" operation on an accumulator that grows linearly with the number of digits already consumed, so the whole loop is O(n²) in the literal length. The lexer regex places no upper bound on the literal length, so a single TOML document containing one ~500 kB hex literal pins one CPU core for ~40 seconds on a modern laptop (Apple M-series, Node v22). Memory amplification is bounded but CPU amplification is severe and grows quadratically: doubling the literal length quadruples the work. A caller that invokes "load()" on attacker-controlled TOML (configuration upload endpoints, CI/CD systems ingesting third-party "*.toml", IDE plugins, build tools) is exposed to a single-request CPU exhaustion DoS. Version 1.1.1 fixes the issue.
Affected Packages
https://github.com/sunnyadn/js-toml.git (GITHUB):
Affected version(s) >=v0.1.0 <v1.1.1Fix Suggestion:
Update to version v1.1.1js-toml (NPM):
Affected version(s) >=0.1.0 <1.1.1Fix Suggestion:
Update to version 1.1.1Related Resources (3)
Do you need more information?
Contact UsCVSS v4
Base Score:
8.7
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
NONE
Vulnerable System Integrity
NONE
Vulnerable System Availability
HIGH
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
7.5
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Weakness Type (CWE)
EPSS
Base Score:
0.41