CVE-2026-54270

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.

Database specific

{
    "cwe_ids": [
        "CWE-770"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/54xxx/CVE-2026-54270.json",
    "cna_assigner": "GitHub_M"
}

References

Affected packages

Git / github.com/protobufjs/protobuf.js

Affected ranges

Type

GIT

Repo

https://github.com/protobufjs/protobuf.js

Events

Introduced

f8d5f3fe7104fade45407341228f0f0bb623e76d

Fixed

4655f8d0a326014fd4c4eb85df39a1837673b28a

Database specific

Show details

{
    "cpe": "cpe:2.3:a:protobufjs_project:protobufjs:*:*:*:*:*:node.js:*:*",
    "extracted_events": [
        {
            "introduced": "8.2.0"
        },
        {
            "fixed": "8.5.0"
        }
    ],
    "source": [
        "AFFECTED_FIELD",
        "CPE_RANGE"
    ]
}

Affected versions

protobufjs-cli-v2.*

protobufjs-cli-v2.2.0

protobufjs-cli-v2.2.1

protobufjs-cli-v2.3.0

protobufjs-cli-v2.4.0

protobufjs-cli-v2.4.1

protobufjs-cli-v2.4.2

protobufjs-v8.*

protobufjs-v8.2.0

protobufjs-v8.2.1

protobufjs-v8.3.0

protobufjs-v8.4.0

protobufjs-v8.4.1

protobufjs-v8.4.2

Database specific

source

"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-54270.json"