Vulnerability · Published Sep 4, 2026 · Assigned by GitHub_M

CVE-2026-85730smol-toml: Denial of Service via malformed TOML documents

High 8.2

In plain English

A high-severity infinite loop in smol-toml from squirrelchat. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 45% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 4.0)8.2High

Exploit odds (30 days)0.5%top 55.4% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

smol-toml is a small, fast, and correct TOML parser and serializer. Prior to 1.7.1, parse() can enter an infinite loop when a value inside an array or inline table is followed by a comment with no trailing newline. In src/util.ts, skipUntil() calls indexOfNewline(), receives -1 at the end of input, and resets the cursor to the beginning of the string instead of leaving the structure scan. The parser then hangs indefinitely and can consume a service's processing capacity when an application parses attacker-controlled TOML. This issue is fixed in version 1.7.1.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
npm	smol-toml	1.7.1	GHSA-7w5x-hrqm-74c2

Affected products (as reported)

Vendor	Product	Versions
squirrelchat	smol-toml	< 1.7.1

Weakness: CWE-606, CWE-835 · Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

References

https://github.com/squirrelchat/smol-toml/security/advisories/GHSA-7w5x-hrqm-74c2 x_refsource_CONFIRM
https://github.com/squirrelchat/smol-toml/commit/30f5c367d946b695f379b5d4f0946b2f0a0a8c2f x_refsource_MISC
https://github.com/squirrelchat/smol-toml/releases/tag/v1.7.1 x_refsource_MISC
https://medium.com/@ravindu.lakmina1/seven-bytes-that-freeze-a-node-js-server-forever-the-story-of-cve-2026-85730-3213328b38f0 x_refsource_MISC