CVE Watch4 de nov. de 2026

CVE-2026-110910

### Summary `qs.stringify` with `allowEmptyArrays: true` writes the key of an empty array without encoding it, even though keys are encod

CVSS

3.7

Baixa

EPSS

0.3%

p21

KEV

—

Exploit Today

0-100

Publicado: 27 de out. de 2026 · Última mod.: 4 de nov. de 2026 · CWE-116

EPSS · 30d

0.2%EPSS · 30 dias0.3%

2026-10-272026-11-07

Descrição técnica

### Summary `qs.stringify` with `allowEmptyArrays: true` writes the key of an empty array without encoding it, even though keys are encoded by default. A key that contains `&` (or the configured `delimiter`), `=`, or `#` therefore becomes query string syntax instead of data, so a caller-supplied key name can add parameters to the serialized query string, or cut it short. ### Details In `lib/stringify.js`, the `allowEmptyArrays` branch returns `adjustedPrefix + '[]'` early, before the code that passes every other key through `encoder` and `formatter`. So `{ "x&k=v": ["1"] }` serializes as `x%26k%3Dv%5B0%5D=1`, but `{ "x&k=v": [] }` serializes as `x&k=v[]`. The early return applies at any depth (`{ "a": { "b&k=v": [] } }` gives `a[b&k=v][]`), under every `arrayFormat`, with `allowDots`, and with a custom `encoder`, which is never called for that key. With `encode: false` or `encodeValuesOnly: true`, keys are intentionally left unencoded on every path; those configurations are not affected. #### PoC ```js var qs = require("qs"); var query = qs.stringify({ q: "hi", "x&apiKey=evil&y": [] }, { allowEmptyArrays: true }); // "q=hi&x&apiKey=evil&y[]" qs.parse(query); // { q: "hi", x: "", apiKey: "evil", y: [""] } qs.stringify({ "x#": [], z: "1" }, { allowEmptyArrays: true }); // "x#[]&z=1": in a URL, everything after "#" becomes the fragment ``` #### Fix Applied in 234d505 on `main` and released as v6.17.0, and backported to v6.16.2, v6.15.4, v6.14.3, v6.13.4, and v6.12.6: the key of an empty array goes through `encoder` and `formatter` exactly as the key of any other value does, so `{ "x&apiKey=evil&y": [] }` now serializes as `x%26apiKey%3Devil%26y[]`. Keys that need no encoding serialize as before, with two exceptions that match every other path: the brackets of a nested key are now encoded (`a[b][]` becomes `a%5Bb%5D[]`, which `qs.parse` reads identically), and with `encodeDotInKeys`, a dot in the key becomes `%252E` instead of `%2E` (which `decodeDotInKeys` previously misread as nesting). ### Affected versions - `>=6.12.0 <6.12.6`, fixed in v6.12.6 - `>=6.13.0 <6.13.4`, fixed in v6.13.4 - `>=6.14.0 <6.14.3`, fixed in v6.14.3 - `>=6.15.0 <6.15.4`, fixed in v6.15.4 - `>=6.16.0 <6.16.2`, fixed in v6.16.2 v6.17.0 and later are not affected. `allowEmptyArrays` was introduced in f22b2bc and first shipped in v6.12.0, with this early return. Earlier versions have no `allowEmptyArrays` option and are not affected. ### Impact An application that passes an object whose key names come from untrusted input to `qs.stringify` with `allowEmptyArrays: true` (for example, to forward a parsed JSON body or user-selected fields to an upstream service) can have parameters injected into the resulting query string. The injected parameters are not keys of the object, so deleting or overwriting a key on the object (such as setting a trusted `apiKey` after copying the user's fields) does not remove them; whether the attacker's value or the application's wins depends on how the receiving side handles a duplicate parameter. A `#` in such a key ends the query string early when the result is placed in a URL. `allowEmptyArrays` is off by default, and only keys whose value (after any `filter`) is an empty array are affected.

Referências oficiais

CVEs relacionados

CVECVSSEPSSKEVRExploitTítuloMod.

CVE-2026-1235402.0 BAI

—

———OpenAM before 16.1.4 contains an incomplete output encoding vulnerability that allows a SAML 1.x identity provider to alter attribute values by injecting unencoded content into the service provider auto-submitted form. Attackers controlling a trusted identity provider can craft assertion attribute names or values that reach the target application in modified form, undermining the integrity of received attributes.12h CVE-2026-1030225.3 MÉD

41.1%

——12Urwid is a console user interface library for Python. Prior to 4.0.7, handle_short_request() in urwid/display/web.py performs unguarded character encoding on POST input and unguarded UTF-8 decoding on polling update socket output. A remote attacker who obtains a valid X-Urwid-ID session token can submit non-ASCII POST data that raises UnicodeEncodeError, while non-UTF-8 polling output raises UnicodeDecodeError, causing the CGI handler to return an error and terminate request processing. The POST exception path also leaves an opened file descriptor unclosed for the CGI process lifetime, so repeated requests can cause denial of service for the web display interface. This issue is fixed in version 4.0.7.2d CVE-2026-102530—

36.2%

——11JupyterLab Desktop is the cross-platform desktop application for JupyterLab. Prior to 4.6.2-1, remote-server URLs were inserted into the server-selection dialog and Welcome view without safe encoding. An attacker who convinces a user to submit a crafted URL can execute JavaScript in the Welcome renderer and abuse its privileged IPC bridge to execute arbitrary code with the user’s privileges. The Welcome view also unsafely renders RSS news-feed titles; exploitation through this separate input path requires control over content delivered through the application’s Jupyter Blog feed or its cached feed data, rather than submission of a remote-server URL. This issue affects all supported platforms and is fixed in version 4.6.2-1.2d CVE-2026-102345—

15.6%

——5Zammad is a web based open source helpdesk/customer support system. Prior to 7.1.2, the new Vue-based ticket interface can render ticket article content without the expected output encoding. An authenticated user can store markup in an article that is interpreted when another user views the ticket, enabling stored cross-site scripting. The default Content Security Policy limits practical impact, and the classic REST/CoffeeScript interface is not affected. This issue is fixed in version 7.1.2.4d CVE-2026-120647—

10.6%

——3CGI versions before 5.00 for Perl allow Content-Disposition parameter injection via unescaped double quotes in the header attachment filename. header(-attachment => $name) writes $name into the quoted filename parameter of Content-Disposition without escaping double quotes. An application that passes request data as the attachment name can be made to send a second filename parameter, changing the name the response is saved under.4d CVE-2026-120644—

10.6%

——3CGI::Cookie versions before 5.00 for Perl allow cookie attribute injection via unvalidated path, domain and expires values. The path, domain and expires values are written into the Set-Cookie header without checking for semicolons or control characters. An application that sets them from request data can be made to add other cookie attributes, such as Domain or SameSite.4d