KEVWire

Security intelligence, with context.

Response snapshot Oct 27, 2026, 03:57 UTC

Back to the wire
Permalink
VulnerabilityCVE-2026-114141

toml-node: Quadratic-complexity DoS via many array-of-tables headers in toml.parse()

`toml.parse()` is vulnerable to a quadratic-complexity (O(n²)) denial-of-service via many array-of-tables (`[[name]]`) headers. `addTableArray()` in `lib/compiler.

Published Updated

At a glance

Exploited
Not known
Severity
8.7 High (CVSS 4.0)
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-4qx8-w7c3-pj3p (opens a new tab)

What happened

## Summary

`toml.parse()` is vulnerable to a quadratic-complexity (O(n²)) denial-of-service via many array-of-tables (`[[name]]`) headers. `addTableArray()` in `lib/compiler.js` rescans two entire bookkeeping Sets on every `[[name]]` header without pruning unrelated or distinct entries, so a document containing n such headers costs O(n²) compiler work. A ~321KB document of 20,000 distinct-named `[[name]]` blocks takes ~10.

3 seconds to parse — a completely ordinary-looking TOML shape (a flat settings block plus one or more array-of-tables sections), not a contrived edge case. This is a separate, unpatched code path from the previously fixed stack-overflow DoS (`GHSA-82x6-q7mm-w9cf`) and requires no key nesting or dotted keys at all.

## Affected component / version

Continue reading

- Package: `toml` (npm), repository `BinaryMuse/toml-node` - Function: `addTableArray()` in `lib/compiler.js` - Confirmed present in the audited checkout at commit `1b2ac40` (2026-07-16), one commit past the `v5.0.0` tag (a changelog-only change) — i.e. present in `v5.0.0`, the latest release. Not exhaustively verified against every prior release, but the affected function is unrelated to `v5.0.

0`'s BigInt/Temporal changes (per `CHANGELOG.md`), so the defect likely predates that release as well.

## Details

`toml.parse(input, options)` (`index.js:5-9`) forwards the caller-supplied string to `parser.parse()` and then `compiler.compile()` with no length or structural validation. Every `[[name]]` (array-of-tables) header is routed (`reduce()`, `lib/compiler.js:43`) to `addTableArray()` (`lib/compiler.js:218-245`), which performs two full linear scans on every call:

```js assignedPaths.forEach(function(p) { if (isSameOrSubPath(p, quotedPath)) assignedPaths.delete(p); }); valueAssignments.forEach(function(p) { if (isSameOrSubPath(p, quotedPath)) valueAssignments.delete(p); }); ``` (`lib/compiler.js:228-233`)

`assignedPaths` and `valueAssignments` accumulate one entry per top-level key/table/array path ever assigned in the entire document. Each scan prunes only entries matching the *currently reopened* path via `isSameOrSubPath()` (`lib/compiler.js:319-321`: `path === prefix || path.indexOf(prefix + ".")

=== 0`); anything else — an unrelated top-level key, or simply a *different* array-of-tables name — is never removed and is rescanned in full on every subsequent `[[name]]` header for the rest of the parse. `Set.prototype.forEach` has no early exit, so this is unconditionally O(current Set size) on every call, giving O(n²) total work for n such headers.

## Proof of Concept

The sharpest reproduction needs no unrelated keys at all — just N array-of-tables headers with N *distinct* names, since nothing is ever pruned when no name repeats:

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

function distinctArrayHeaders(n) { let out = ''; for (let i = 0; i >` keyed by the first key component) so `addTableArray()` only ever scans the bucket relevant to the path being reopened, in time proportional to that bucket's size rather than the whole document's accumulated path count:

```js var assignedByRoot = new Map(); // root segment -> Set

function addTableArray(node) { var path = node.value; var root = path[0]; var bucket = assignedByRoot.get(root) || new Set(); bucket.forEach(function(p) { if (isSameOrSubPath(p, quotedPath)) bucket.delete(p); }); // ...rest of addTableArray unchanged, reading/writing the per-root bucket // instead of the global assignedPaths/valueAssignments Sets } ```

As with the sibling finding, an input-size or table-count limit would also help as defense-in-depth.

## Credit

Discovered and reported by SecDim Security Research secdim.com | @secdim | security@secdim.com

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

Scores and how they were measured

CVSS base severity

8.7

Version 4.0As of

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

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 33.5%

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-4qx8-w7c3-pj3p (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-4qx8-w7c3-pj3p, 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-4qx8-w7c3-pj3p, 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-4qx8-w7c3-pj3p, 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-4qx8-w7c3-pj3p, 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-4qx8-w7c3-pj3p, 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-4qx8-w7c3-pj3p, 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-4qx8-w7c3-pj3p, 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-4qx8-w7c3-pj3p, 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-4qx8-w7c3-pj3p, 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-4qx8-w7c3-pj3p, its actual identifiers, source dates, and structured metrics.

    Published Date not suppliedChecked

  12. Primary source

    NVD CVE-2026-114141 (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-2026-114141, 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 23). toml-node: Quadratic-complexity DoS via many array-of-tables headers in toml.parse() (CVE-2026-114141). https://kevwire.com/record/CVE-2026-114141

MLA

"toml-node: Quadratic-complexity DoS via many array-of-tables headers in toml.parse() (CVE-2026-114141)." KEVWire, 23 Oct. 2026, kevwire.com/record/CVE-2026-114141.

Chicago

KEVWire. "toml-node: Quadratic-complexity DoS via many array-of-tables headers in toml.parse() (CVE-2026-114141)." Last modified October 23, 2026. https://kevwire.com/record/CVE-2026-114141.

Evidence summary (plain text)

toml-node: Quadratic-complexity DoS via many array-of-tables headers in toml.parse() (Oct 22, 2026).
`toml.parse()` is vulnerable to a quadratic-complexity (O(n²)) denial-of-service via many
array-of-tables (`[[name]]`) headers. `addTableArray()` in `lib/compiler.js` rescans two
entire bookkeeping Sets on every `[[name]]` header without pruning unrelated or distinct
entries, so a document containing n such headers costs O(n²) compiler work. A ~321KB document
of 20,000 distinct-named `[[name]]` blocks takes ~10.3 seconds to parse — a completely
ordinary-looking TOML shape (a flat settings block plus one or more array-of-tables sections),
not a contrived edge case. This is a separate, unpatched code path from the previously fixed
stack-overflow DoS (`GHSA-82x6-q7mm-w9cf`) and requires no key nesting or dotted keys at all.

- Package: `toml` (npm), repository `BinaryMuse/toml-node`
- Function: `addTableArray()` in `lib/compiler.js`
- Confirmed present in the audited checkout at commit `1b2ac40` (2026-07-16), one commit past
 the `v5.0.0` tag (a changelog-only change) — i.e. present in `v5.0.0`, the latest release.
 Not exhaustively verified against every prior release, but the affected function is
 unrelated to `v5.0.0`'s BigInt/Temporal changes (per `CHANGELOG.md`), so the defect likely
 predates that release as well.
CVSS 8.7 (version 4.0; evidence as of Oct 23, 2026; https://nvd.nist.gov/vuln/detail/CVE-2026-114141).
EPSS 0.4% for the following 30 days, scored Oct 26, 2026 (https://api.first.org/data/v1/epss?cve=CVE-2026-114141&date=2026-10-26).
Sources:
GitHub-reviewed advisory GHSA-4qx8-w7c3-pj3p: https://github.com/advisories/GHSA-4qx8-w7c3-pj3p
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-2026-114141: https://nvd.nist.gov/vuln/detail/CVE-2026-114141
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-2026-114141&date=2026-10-26
Record ID: CVE-2026-114141.
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.

Record JSON

Your account

Email alerts

Email alerts are not available yet. To follow your stack today, use its RSS feed, which honors your filters, or connect an AI agent through the API.

Suggest an improvement

Ideas, missing sources, corrections, and bugs are all welcome. No account needed. Suggestions are reviewed by a person before anything changes.

Record details

Record detail