PT-2026-51007 · Sunnyadn · Js-Toml

Published

2026-06-19

·

Updated

2026-06-19

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CVE-2026-49293

CVSS v3.1

7.5

High

VectorAV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
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.

Fix

DoS

Resource Exhaustion

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Weakness Enumeration

Related Identifiers

CVE-2026-49293

Affected Products

Js-Toml