CVE-2026-54270

MEDIUM
MEDIUM Priority: 0.02 BB Relevance: 71/100
Published: 2026-06-22 Modified: 2026-10-25 First seen: 2026-10-29 Status: active

Attack Surface

Network Low Complexity No Auth No Interaction

CVSS Vector Breakdown

AV: Network
AC: Low
PR: None
UI: None
S: Unchanged
C: None
I: None
A: Low

Description

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.

Weakness Classification (1)

Affected Software (1)

VendorProductVersion
protobufjs_project protobufjs 8.2.0 – 8.5.0

References & Advisories (1)

Bug Bounty Relevance

71 / 100
✓ Network accessible
✓ No authentication
✓ Low complexity
✓ No user interaction

CVSS Score

5.3 / 10.0 v3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

EPSS — Exploitation Probability

0.40%
Raw Score 0.004020
Percentile 34.4%
Date 2026-10-29

EPSS Trend

2026-10-29
0.00402
2026-10-28
0.00402

Intelligence Sources

nvd ref →