CVE-2026-55091High· 7.5▾ Twilightflat-to-nested converts a hierarchy from a flat representation to a nested representation. Prior to 1.1.2, FlatToNested.prototype.convert in index.js uses attacker-influenced id and parent record fields directly as keys in the plain temp…
▾ Twilight zone — High severity, or a signal on a lesser flaw
impact 41.3 · likelihood 0.1 · exploitation 0
Need a working PoC? Pro members can cast a request and our team develops one — it lands right here.
Stakeholder-Specific Vulnerability Categorization from CISA's ADP record at CVE.org: whether exploitation is observed, whether an attack can be automated, and how much of the system is at stake.
Exploit-prediction probability, daily snapshots since Sep 15.
Disclosure to exploitation, from the record and what we observed since indexing it.
Disclosed via NVD
0.4%
flat-to-nested converts a hierarchy from a flat representation to a nested representation. Prior to 1.1.2, FlatToNested.prototype.convert in index.js uses attacker-influenced id and parent record fields directly as keys in the plain temp and pendingChildOf objects. When parent or id is proto, temp[parent] can resolve to Object.prototype, and initPush() can write attacker-controlled data to the global children prototype property while existing prototype methods remain intact. Any application that passes attacker-influenced flat records to convert() can therefore expose unrelated objects to polluted inherited state, causing application-logic corruption or denial of service and potentially enabling greater impact when a downstream prototype-pollution gadget is present. The constructor and prototype strings are also unsafe inherited-key values in the same lookup design. This issue is fixed in version 1.1.2.
Refer to the linked advisories for vendor-supplied fixes and affected version ranges.
Affected packages:
flat-to-nested <= 1.1.1Patched in:
flat-to-nested 1.1.2Connected by shared product, vendor, weakness, or advisory.
CVE-2026-55451High· 8.3gettext-converter provides gettext resource conversion utilities for JavaScript
CVE-2026-90771Low· 3.7joi before versions 17.13.8 and 18.2.9 contains a prototype pollution vulnerability in the messages compilation function that accepts __proto__ as an error code
CVE-2026-85063Medium· 6.5node-csv is a full-featured CSV parser with a simple API that is tested against large datasets
CVE-2026-63376High· 8.2toml-node is a TOML parser for Node.js and the browser
CVE-2026-73088High· 7.5Browserslist is a configuration tool for sharing target browsers and Node.js versions between front-end tools
CVE-2026-46625High· 7.5JavaScript Cookie is a JavaScript API for handling cookies, client-side