Detections
Analytics

SCA: security update for defu (GHSA-737v-mqg7-c878)

high Tenable Cloud Security Plugin ID 439827

Description

There are packages installed that are affected by a vulnerability referenced in the following CVE:

 - defu is software that allows uers to assign default properties recursively. Prior to version 6.1.5,
 applications that pass unsanitized user input (e.g. parsed JSON request bodies, database records, or
 config files from untrusted sources) as the first argument to `defu()` are vulnerable to prototype
 pollution. A crafted payload containing a `__proto__` key can override intended default values in the
 merged resul. The internal `_defu` function used `Object.assign({}, defaults)` to copy the defaults
 object. `Object.assign` invokes the `__proto__` setter, which replaces the resulting object's
 `[[Prototype]]` with attacker-controlled values. Properties inherited from the polluted prototype then
 bypass the existing `__proto__` key guard in the `for...in` loop and land in the final result. Version
 6.1.5 replaces `Object.assign({}, defaults)` with object spread (`{ ...defaults }`), which uses
 `[[DefineOwnProperty]]` and does not invoke the `__proto__` setter. (CVE-2026-35209)

Solution

Update the defu library and its related packages to version 6.1.5 or later.

See Also

https://github.com/advisories/GHSA-737v-mqg7-c878

Plugin Details

Severity: High

ID: 439827

Version: Revision 1.6

Type: Local

Family: SCA Checks

Published: 4/4/2026

Updated: 7/2/2026

Supported Sensors: Tenable Cloud Security, Tenable Self-Hosted Container Security

Risk Information

VPR

Risk Factor: Medium

Score: 5

Percentile: 94.15

Vendor

Vendor Severity: High

CVSS v2

Risk Factor: High

Base Score: 7.8

Temporal Score: 5.8

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:C/A:N

CVSS Score Source: CVE-2026-35209

CVSS v3

Risk Factor: High

Base Score: 7.5

Temporal Score: 6.5

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

Exploit Ease: No known exploits are available

Patch Publication Date: 4/4/2026

Vulnerability Publication Date: 4/4/2026

Reference Information

CVE: CVE-2026-35209