GHSA-v3rj-xjv7-4jmq — smol-toml
MEDIUMGHSA-v3rj-xjv7-4jmq is a medium-severity (CVSS 5.3) remote code execution vulnerability in smol-toml. A fix is available for smol-toml — see the affected versions and patch details below.
smol-toml: Denial of Service via TOML documents containing thousands of consecutive commented lines
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
smol-tomlnpmDescription
Summary
An attacker can send a maliciously crafted TOML to cause the parser to crash, because of a stack overflow caused by thousands of consecutive commented lines.
The library uses recursion internally while parsing to skip over commented lines, which can be exploited to crash an application that is processing arbitrary TOML documents.
Proof of concept
require("smol-toml").parse('# comment\n'.repeat(8000) + 'key = "value"')
Impact
Applications which parse arbitrary TOML documents may suffer availability issues if they receive malicious input. If uncaught, the crash may cause the application itself to crash. The impact is deemed minor, as the function is already likely to throw errors on invalid input. Downstream users are supposed to properly handle errors in such situations.
Due to the design of most JavaScript runtimes, the uncontrolled recursion does not lead to excessive memory usage and the execution is quickly aborted.
As a reminder, it is strongly advised when working with untrusted user input to expect errors to occur and to appropriately catch them.
Patches
Version 1.6.1 uses a different approach for parsing comments, which no longer involves recursion.
Workarounds
Wrap all invocations of parse and stringify in a try/catch block when dealing with untrusted user input.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | smol-toml | all versions | 1.6.1npm install smol-toml@1.6.1 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for smol-toml, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update smol-toml to 1.6.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-v3rj-xjv7-4jmq is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-v3rj-xjv7-4jmq can be triaged on real exposure rather than presence alone.
Tailored to GHSA-v3rj-xjv7-4jmq. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-v3rj-xjv7-4jmq in your dependencies?
O3 Security finds GHSA-v3rj-xjv7-4jmq across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.