Описание
smol-toml: Denial of Service via malformed TOML documents
Summary
parse() can be forced into an infinite loop when a value inside an array or inline table is followed by a comment that has no trailing newline (i.e. the comment "ends" the document).
The library fails to exit an internal loop when attempting to find the end of the structure, resetting its cursor to the beginning of the string instead. This causes the parser to indefinitely hang, compromising the availability of the service.
Proof of concept
Impact
Applications which parse arbitrary TOML documents can suffer major availability issues if they receive malicious input. This issue is particularly severe for these use-cases, and it is strongly advised to upgrade to an up-to-date version of the library as soon as possible.
If your use-case does not involve parsing arbitrary TOML documents from untrusted sources, the impact is much lower in practice, although it's still advisable to update to version 1.7.1.
Patches
Version 1.7.1 properly breaks out of the loop in these situations and throws the expected TomlError.
Workarounds
None that don't involve refactors. Update the library as soon as possible if your use-case involves parsing arbitrary TOML documents from untrusted sources.
Reported By : Ravindu Lakmina Munaweera
Ссылки
- https://github.com/squirrelchat/smol-toml/security/advisories/GHSA-7w5x-hrqm-74c2
- https://nvd.nist.gov/vuln/detail/CVE-2026-85730
- https://github.com/squirrelchat/smol-toml/commit/30f5c367d946b695f379b5d4f0946b2f0a0a8c2f
- https://github.com/squirrelchat/smol-toml/releases/tag/v1.7.1
- https://medium.com/@ravindu.lakmina1/seven-bytes-that-freeze-a-node-js-server-forever-the-story-of-cve-2026-85730-3213328b38f0
Пакеты
smol-toml
<= 1.7.0
1.7.1
Связанные уязвимости
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.
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.