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Response snapshot Oct 27, 2026, 03:07 UTC

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VulnerabilityCVE-2026-114144

toml-node: Uncontrolled resource consumption (CPU DoS) via unbounded-length integer literals in toml.parse()

- `lib/parser.js:326` — hex: `BigInt('0x' + stripUnderscores(digits))` - `lib/parser.js:327` — octal: `BigInt('0o' + stripUnderscores(digits))` - `lib/parser.js:328` — binary: `BigInt('0b' + stripUnderscores(digits))` - `lib/parser.

Published Updated

At a glance

Exploited
Not known
Severity
7.5 High (CVSS 3.1)
Chance of exploitation
0.4% in the next 30 days
Sources
2 independent sources

What to do

GitHub lists first patched versions: toml: 5.0.1. Confirm the affected range and upgrade guidance in the exact advisory.

Read GitHub-reviewed advisory GHSA-9qmh-m7c6-f92p (opens a new tab)

What happened

### Summary `toml.parse()` converts integer literals (hex, octal, binary, and decimal) to `BigInt` without first bounding the length of the digit sequence. Since `BigInt(string)` construction from a very long numeric string runs in super-linear time, a single small, well-formed TOML document containing one long integer literal can pin a Node.

js process's event loop at 100% CPU for several seconds — a denial of service for any application that parses attacker-supplied or third-party TOML. No authentication or complex crafting is required.

### Details In `lib/parser.js`, the grammar actions that build integer nodes call `BigInt()` directly on the matched digit text, with no upper bound on its length:

- `lib/parser.js:326` — hex: `BigInt('0x' + stripUnderscores(digits))` - `lib/parser.js:327` — octal: `BigInt('0o' + stripUnderscores(digits))` - `lib/parser.js:328` — binary: `BigInt('0b' + stripUnderscores(digits))` - `lib/parser.js:329` — decimal: `BigInt(stripUnderscores(text))`

Continue reading

The parser does enforce a nesting-depth limit (`MAX_DEPTH`, default 500, `lib/parser.js:4343`) to guard against stack overflow from deeply nested arrays/inline tables (per GHSA-82x6-q7mm-w9cf). However, that guard only bounds *structural nesting* — it does not bound the length of a single scalar token.

The subsequent 64-bit range check in `lib/compiler.js` (`reduceInteger`, lines 143–150, comparing against `INT64_MIN` / `INT64_MAX` defined at lines 3–4) happens **after** the expensive `BigInt()` conversion has already completed. It therefore provides no protection against this cost — the CPU time is already spent by the time the value is rejected as out of range.

### PoC

```js const toml = require('toml');

const N = 5_000_000; // ~5 MB request body const doc = 'x = 0x' + 'f'.repeat(N);

const start = Date.now(); try { toml.parse(doc); // eventually throws "outside the 64-bit signed integer range" — // but only after the costly conversion has run } catch (e) {}

console.log('elapsed:', Date.now() - start, 'ms'); ```

**Measured results:**

| Digits (hex) | Approx. payload size | Parse time | |---:|---:|---:| | 200,000 | ~200 KB | 141 ms | | 400,000 | ~400 KB | 276 ms | | 800,000 | ~800 KB | 685 ms | | 1,600,000 | ~1.6 MB | 1,761 ms | | 5,000,000 | ~5 MB | 6,061 ms |

Growth is clearly super-linear. The same behavior reproduces for plain decimal literals (3,000,000 `'9'` digits → ~6.3 s).

### Impact Any application that calls `toml.parse()` on untrusted or third-party input — config upload endpoints, CI/CD tools ingesting user-supplied `.toml` files, package managers, linters, editors/language servers — is exposed.

During the conversion, the event loop is fully blocked. In a typical single-threaded Node.js server this stalls **all** concurrent request handling, not just the request containing the malicious payload. A single ~5 MB request is sufficient to cause several seconds of full CPU denial of service.

**Suggested fix:** Reject digit sequences above a reasonable length *before* calling `BigInt()`, analogous to the existing `maxDepth` option. A 64-bit signed integer requires at most 20 decimal digits or 16 hex digits, so any digit sequence significantly longer than that is guaranteed to fail the existing range check anyway, and can be rejected with a cheap `.length` comparison instead of paying for the full `BigInt` conversion.

Affected package ranges reported by GitHub: toml: <= 5.0.0

Scores and how they were measured

CVSS base severity

7.5

Version 3.1As of

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Measurement source (opens a new tab)

How bad it is if exploited. Not a prediction of exploitation or proof you are exposed.

EPSS probability

0.4%

Scored Percentile 38.0%

Model and measurement source (opens a new tab)

A model's estimate of exploitation in the next 30 days, not certainty or your own risk.

Related technology

Sources

  1. Primary source

    GitHub-reviewed advisory GHSA-9qmh-m7c6-f92p (opens a new tab)

    The public advisory supplies the description, affected package/version ranges, and any listed CVSS metric. GitHub review is not local review.

    Published Checked

  2. Primary source

    GitHub public advisory API page (opens a new tab)

    The API page supplied GHSA-9qmh-m7c6-f92p, its actual identifiers, source dates, and structured metrics.

    Published Date not suppliedChecked

  3. Primary source

    GitHub public advisory API page (opens a new tab)

    The API page supplied GHSA-9qmh-m7c6-f92p, its actual identifiers, source dates, and structured metrics.

    Published Date not suppliedChecked

  4. Primary source

    GitHub public advisory API page (opens a new tab)

    The API page supplied GHSA-9qmh-m7c6-f92p, its actual identifiers, source dates, and structured metrics.

    Published Date not suppliedChecked

  5. Primary source

    GitHub public advisory API page (opens a new tab)

    The API page supplied GHSA-9qmh-m7c6-f92p, its actual identifiers, source dates, and structured metrics.

    Published Date not suppliedChecked

  6. Primary source

    GitHub public advisory API page (opens a new tab)

    The API page supplied GHSA-9qmh-m7c6-f92p, its actual identifiers, source dates, and structured metrics.

    Published Date not suppliedChecked

  7. Primary source

    GitHub public advisory API page (opens a new tab)

    The API page supplied GHSA-9qmh-m7c6-f92p, its actual identifiers, source dates, and structured metrics.

    Published Date not suppliedChecked

  8. Primary source

    GitHub public advisory API page (opens a new tab)

    The API page supplied GHSA-9qmh-m7c6-f92p, its actual identifiers, source dates, and structured metrics.

    Published Date not suppliedChecked

  9. Primary source

    GitHub public advisory API page (opens a new tab)

    The API page supplied GHSA-9qmh-m7c6-f92p, its actual identifiers, source dates, and structured metrics.

    Published Date not suppliedChecked

  10. Primary source

    GitHub public advisory API page (opens a new tab)

    The API page supplied GHSA-9qmh-m7c6-f92p, its actual identifiers, source dates, and structured metrics.

    Published Date not suppliedChecked

  11. Primary source

    GitHub public advisory API page (opens a new tab)

    The API page supplied GHSA-9qmh-m7c6-f92p, its actual identifiers, source dates, and structured metrics.

    Published Date not suppliedChecked

  12. Primary source

    NVD CVE-2026-114144 (opens a new tab)

    NVD record: description, CVSS (the CNA score is preferred), affected products, and publication date. Not evidence of exploitation.

    Published Checked

  13. Primary source

    NVD CVE API 2.0 (opens a new tab)

    The NVD API page that supplied this CVE record.

    Published Date not suppliedChecked

  14. Primary source

    FIRST measured EPSS score (opens a new tab)

    Measured EPSS probability and percentile for CVE-2026-114144, scored 2026-10-26. This is a model estimate, not proof of exposure.

    Published Checked

Cite this record

For factual claims, cite the primary sources above; cite KEVWire for its compilation, dates, and classifications.

APA

KEVWire. (2026, October 22). toml-node: Uncontrolled resource consumption (CPU DoS) via unbounded-length integer literals in toml.parse() (CVE-2026-114144). https://kevwire.com/record/CVE-2026-114144

MLA

"toml-node: Uncontrolled resource consumption (CPU DoS) via unbounded-length integer literals in toml.parse() (CVE-2026-114144)." KEVWire, 22 Oct. 2026, kevwire.com/record/CVE-2026-114144.

Chicago

KEVWire. "toml-node: Uncontrolled resource consumption (CPU DoS) via unbounded-length integer literals in toml.parse() (CVE-2026-114144)." Last modified October 22, 2026. https://kevwire.com/record/CVE-2026-114144.

Evidence summary (plain text)

toml-node: Uncontrolled resource consumption (CPU DoS) via unbounded-length integer literals in toml.parse() (Oct 22, 2026).
- `lib/parser.js:326` — hex: `BigInt('0x' + stripUnderscores(digits))`
- `lib/parser.js:327` — octal: `BigInt('0o' + stripUnderscores(digits))`
- `lib/parser.js:328` — binary: `BigInt('0b' + stripUnderscores(digits))`
- `lib/parser.js:329` — decimal: `BigInt(stripUnderscores(text))`

The parser does enforce a nesting-depth limit (`MAX_DEPTH`, default 500, `lib/parser.js:4343`) to guard against stack overflow from deeply nested arrays/inline tables (per GHSA-82x6-q7mm-w9cf). However, that guard only bounds *structural nesting* — it does not bound the length of a single scalar token.
CVSS 7.5 (version 3.1; evidence as of Oct 22, 2026; https://nvd.nist.gov/vuln/detail/CVE-2026-114144).
EPSS 0.4% for the following 30 days, scored Oct 26, 2026 (https://api.first.org/data/v1/epss?cve=CVE-2026-114144&date=2026-10-26).
Sources:
GitHub-reviewed advisory GHSA-9qmh-m7c6-f92p: https://github.com/advisories/GHSA-9qmh-m7c6-f92p
GitHub public advisory API page: https://api.github.com/advisories?type=reviewed&per_page=100&sort=updated&direction=desc&after=Y3Vyc29yOnYyOpK0MjAyNi0xMC0yM1QyMDo1MTozMFrOAAf0Mg%3D%3D
GitHub public advisory API page: https://api.github.com/advisories?type=reviewed&per_page=100&sort=updated&direction=desc&after=Y3Vyc29yOnYyOpK0MjAyNi0xMC0yM1QyMDo0OToxMlrOAAf0LQ%3D%3D
GitHub public advisory API page: https://api.github.com/advisories?type=reviewed&per_page=100&sort=updated&direction=desc&after=Y3Vyc29yOnYyOpK0MjAyNi0xMC0yM1QyMDo0NzoxN1rOAAf0Kg%3D%3D
GitHub public advisory API page: https://api.github.com/advisories?type=reviewed&per_page=100&sort=updated&direction=desc&after=Y3Vyc29yOnYyOpK0MjAyNi0xMC0yM1QyMDo0NTozNlrOAAf0Jw%3D%3D
GitHub public advisory API page: https://api.github.com/advisories?type=reviewed&per_page=100&sort=updated&direction=desc&after=Y3Vyc29yOnYyOpK0MjAyNi0xMC0yM1QyMDo0NTowNVrOAAf0JQ%3D%3D
GitHub public advisory API page: https://api.github.com/advisories?type=reviewed&per_page=100&sort=updated&direction=desc&after=Y3Vyc29yOnYyOpK0MjAyNi0xMC0yM1QyMDo0Mzo0NVrOAAf0Iw%3D%3D
GitHub public advisory API page: https://api.github.com/advisories?type=reviewed&per_page=100&sort=updated&direction=desc&after=Y3Vyc29yOnYyOpK0MjAyNi0xMC0yM1QyMDo0MzozMVrOAAf0Ig%3D%3D
GitHub public advisory API page: https://api.github.com/advisories?type=reviewed&per_page=100&sort=updated&direction=desc&after=Y3Vyc29yOnYyOpK0MjAyNi0xMC0yM1QxODozNTowMVrOAAZRcw%3D%3D
GitHub public advisory API page: https://api.github.com/advisories?type=reviewed&per_page=100&sort=updated&direction=desc&after=Y3Vyc29yOnYyOpK0MjAyNi0xMC0yM1QxODozMDoyN1rOAAY_5Q%3D%3D
GitHub public advisory API page: https://api.github.com/advisories?type=reviewed&per_page=100&sort=updated&direction=desc&after=Y3Vyc29yOnYyOpK0MjAyNi0xMC0yM1QxODoyOTowNVrOAAfz8g%3D%3D
NVD CVE-2026-114144: https://nvd.nist.gov/vuln/detail/CVE-2026-114144
NVD CVE API 2.0: https://services.nvd.nist.gov/rest/json/cves/2.0?pubStartDate=2026-10-12T13:35:55.142Z&pubEndDate=2026-10-26T13:35:55.142Z&resultsPerPage=500&startIndex=8000
FIRST measured EPSS score: https://api.first.org/data/v1/epss?cve=CVE-2026-114144&date=2026-10-26
Record ID: CVE-2026-114144.
Record origin: Ingested record.
AI evidence: Not assessed.
Known exploitation: Not assessed.
Zero-day status: Not assessed. KEV membership alone does not establish zero-day status.
About this data

This record was ingested from a data source. Retrieved: Oct 27, 2026, 01:40 UTC. Ingestion is not an independent editorial investigation.

A CISA KEV listing documents known exploitation, not necessarily a zero-day; absence from the catalog does not prove a vulnerability has never been exploited.

Technology tags indicate possible relevance, not verified exposure. Confirm the affected product, version, and configuration against your own inventory; KEVWire does not scan your systems.

A personal reading checklist on this device, not verified remediation.

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