CVE-2026-21717Medium· 5.9▾ TwilightPoC availableA flaw in V8's string hashing mechanism causes integer-like strings to be hashed to their numeric value, making hash collisions trivially predictable. By crafting a request that causes many such collisions in V8's internal string table, …
▾ Twilight zone — High severity, or a signal on a lesser flaw
impact 32.5 · likelihood 0.1 · exploitation 12
A public proof-of-concept already exists for this vulnerability — see Exploit availability below.
Public exploit / PoC code seen in 1 source. Availability, not in-the-wild use.
Exploit-prediction probability, daily snapshots since Aug 19.
Disclosure to exploitation, from the record and what we observed since indexing it.
Disclosed via NVD
Last analysed / modified upstream
0.3%
1 GitHub repo
A flaw in V8's string hashing mechanism causes integer-like strings to be hashed to their numeric value, making hash collisions trivially predictable. By crafting a request that causes many such collisions in V8's internal string table, an attacker can significantly degrade performance of the Node.js process.
The most common trigger is any endpoint that calls JSON.parse() on attacker-controlled input, as JSON parsing automatically internalizes short strings into the affected hash table.
This vulnerability affects 20.x, 22.x, 24.x, and 25.x.
node.js <= 20.20.1node.js >= 22.0.0, <= 22.22.1node.js >= 24.0.0, <= 24.14.0node.js >= 25.0.0, <= 25.8.1Refer to the linked advisories for vendor-supplied fixes and affected version ranges.
Field changes observed since this record was first indexed.
Connected by shared product, vendor, weakness, or advisory.
CVE-2026-21710High· 7.5A flaw in Node.js HTTP request handling causes an uncaught `TypeError` when a request is received with a header named `__proto__` and the application accesses `req.headersDistinct`. When this occurs, `dest["__proto__"]` resolves to `O…
CVE-2026-21711Medium· 5.3A flaw in Node.js Permission Model network enforcement leaves Unix Domain Socket (UDS) server operations without the required permission checks, while all comparable network paths correctly enforce them. As a result, code running unde…
CVE-2026-21712Medium· 6.5A flaw in Node.js URL processing causes an assertion failure in native code when `url.format()` is called with a malformed internationalized domain name (IDN) containing invalid characters, crashing the Node.js process.
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CVE-2026-21715Low· 3.3A flaw in Node.js Permission Model filesystem enforcement leaves `fs.realpathSync.native()` without the required read permission checks, while all comparable filesystem functions correctly enforce them. As a result, code running under…
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