CVE-2026-44292 | protobufjs: Prototype injection in generated message constructors

protobufjs compiles protobuf definitions into JavaScript (JS) functions. Prior to 7.5.6 and 8.0.2, protobufjs generated message constructors copied enumerable properties from a provided properties object without filtering the __proto__ key. If an application constructed a message from an attacker-controlled plain object, an own enumerable __proto__ property could alter the prototype of that individual message instance. This vulnerability is fixed in 7.5.6 and 8.0.2.

Published: 2026-05-13 Last update: 2026-05-13 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-44292 is rated Low Risk (24.8/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.20%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-44292

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.06% 0.20% +0.14%
2 2026-05-14 — 0.06% —

Full EPSS history (2 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-44292

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.3 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
 3.9 1.4 [email protected]

Weakness enumeration for CVE-2026-44292

GitHub Security Advisory for CVE-2026-44292

GHSA-fx83-v9x8-x52w · Severity: medium · Ecosystem: npm — protobuf.js: Prototype injection in generated message constructors

Affected software / configurations for CVE-2026-44292

Vendor Product Version Raw CPE
protobufjs_project protobufjs < 7.5.6 cpe:2.3:a:protobufjs_project:protobufjs:*:*:*:*:*:node.js:*:*
protobufjs_project protobufjs >= 8.0.0, < 8.0.2 cpe:2.3:a:protobufjs_project:protobufjs:*:*:*:*:*:node.js:*:*

References for CVE-2026-44292

cvelogic Threat Intelligence