toml-node: Uncontrolled Recursion

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

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

EPSS

• CVE-2026-77465: 0.61% estimated exploitation activity in the next 30 days; percentile 49.23 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary toml.parse() crashes with an uncaught RangeError: Maximum call stack size exceeded when parsing deeply nested arrays or inline tables. The parser is generated by Peggy 5.1.0 (a PEG parser generator) as a recursive-descent parser; the value rule mutually recurses with the array and inline-table rules with no depth limit, so nesting depth equal to the input depth exhausts Node's call stack. A small payload — a bare array nested a few thousand levels deep (~5–6 KB) — reliably crashes the process on a default Node.js configuration. toml has ~47 million monthly downloads. --- Vulnerable Code The parser is a generated recursive-descent parser (lib/parser.js, header: // @generated by Peggy 5.1.0.). The recursion sink is the mutual recursion between the value, array, and inlinetable rule functions — none carry a depth counter: Recursion cycle for a=[[[ … ]]] (bare nested arrays): Inline tables ({arr=[ … ]}, {a={a= … }}) reach the same cycle via peg$parseinlinetable /…

Published by the source

3 Sep 2026, 20:56 UTC

Last modified by the source

3 Sep 2026, 20:56 UTC

Source last checked

26 Oct 2026, 13:02 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-82x6-q7mm-w9cf

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# Patch Next advisory brief: CVE-2026-77465

Advisory: toml-node: Uncontrolled Recursion
IDs: CVE-2026-77465, GHSA-82x6-q7mm-w9cf
Record: https://patchnext.com/advisories/cve-2026-77465 (revision 1, source checked 26 Oct 2026, 13:02 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: toml 4.2.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm toml: affected < 4.2.0; fixed in 4.2.0

## Suggested inspection (read-only)
- `npm ls toml --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on toml.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-82x6-q7mm-w9cf (GitHub-reviewed advisory GHSA-82x6-q7mm-w9cf lists affected ranges: npm toml >=0 <4.2.0)

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