GHSA-r4xh-jqrq-34v2: smol-toml

Package	Ecosystem	Affected	Fixed in
smol-toml	npm	<1.9.0	1.9.0

Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

Smol-toml versions before 1.9.0 have a quadratic-time code path in parse() when handling keys, which is reached with default options on ordinary valid TOML, such as a long flat list of key = value lines or repeated table headers. An attacker who can get the service to parse a crafted or large TOML document can make parsing take a very long time, blocking the event loop while it runs. Upgrade to smol-toml 1.9.0 or later, which uses a linear-time key parser; until then, the source suggests limiting the maximum document size accepted for parsing.

Written 31 Oct 2026.

Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

Severity and exploitation

Score	Rating	CVSS	Vector	Source
5.3	Medium	3.1	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L	GitHub Advisory Database

CISA KEV Not listed.
EPSS No score.

Timeline

31 Oct 2026, 13:34 UTC First seen by agentprime
31 Oct 2026, 13:34 UTC Confirmed by OSV

Sources

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.