---
cve: "CVE-2026-54270"
severity: "MEDIUM"
cvss: 5.3
epss: "40%"
vendor: "protobufjs"
kev: false
exploited: false
published: "2026-06-22 18:16:45"
tags: [cve, security, medium]
source: tsecurity.de CVE-Dossier
exported: "2026-09-07T07:04:56+02:00"
---

# CVE-2026-54270

> 5.3 MEDIUM · 🧪 PoC

## Beschreibung

protobufjs compiles protobuf definitions into JavaScript (JS) functions. From 8.2.0 to 8.4.2, protobufjs preserved unknown wire elements in message.$unknowns and did not provide a decode-time option to discard unknown fields before retaining them. A crafted protobuf payload containing many unknown fields could therefore cause a decoded message to retain substantially more memory than the input size would suggest, even when unknown-field round-tripping is not needed. protobufjs 8.5.0 added the relevant decode-time options, allowing applications that decode untrusted protobuf data to disable unknown-field retention during decode. protobufjs 8.6.2 flips the default so unknown fields are discarded unless explicitly opted into.

## CVSS-Vektor

```
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Keine | bad |
| UI Interaktion | Keine | bad |
| S Scope | Unverändert | good |
| C Vertraulichkeit | Keine | good |
| I Integrität | Keine | good |
| A Verfügbarkeit | Gering | warn |

## Patch verfügbar (OSV)

- 4655f8d0a326014fd4c4eb85df39a1837673b28a (Commit)

## Referenzen

- <https://github.com/protobufjs/protobuf.js/security/advisories/GHSA-94rc-8x27-4472>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-54270) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_