protobufjs: Code injection through bytes field defaults in generated toObject code

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protobufjs compiles protobuf definitions into JavaScript (JS) functions. Prior to 7.5.6 and 8.0.2, protobufjs generated JavaScript for toObject conversion could include an unsafe expression derived from a schema-controlled bytes field default value. A crafted descriptor with a non-string default value for a bytes field could cause attacker-controlled code to be emitted into the generated conversion function. This vulnerability is fixed in 7.5.6 and 8.0.2.

Source published

13 May 2026 14:43:33 UTC

Source modified

9 Sep 2026 12:05:01 UTC

Saved here

23 Oct 2026 15:48:27 UTC

Source terms

CVE Program Terms of Use

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CVSS 4.0 · 7.7 CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

protobufjs compiles protobuf definitions into JavaScript (JS) functions. Prior to 7.5.6 and 8.0.2, protobufjs generated JavaScript for toObject conversion could include an unsafe expression derived from a schema-controlled bytes field default value. A crafted descriptor with a non-string default value for a bytes field could cause attacker-controlled code to be emitted into the generated conversion function. This vulnerability is fixed in 7.5.6 and 8.0.2.

Source published

May 13, 2026, 2:43:33 PM (timezone not stated)

Source modified

Sep 9, 2026, 12:05:01 PM (timezone not stated)

Saved here

15 Nov 2026 13:10:55 UTC

Source terms

ENISA EUVD · source terms and attribution apply

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Source: euvd · ENISA EUVD · source terms and attribution apply. The publisher's wording is preserved. ChangeIntel groups the information and labels changes. The JSON record includes additional source fields.

EUVD CVSS 4.0 · 7.7 CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

protobufjs compiles protobuf definitions into JavaScript (JS) functions. Prior to 7.5.6 and 8.0.2, protobufjs generated JavaScript for toObject conversion could include an unsafe expression derived from a schema-controlled bytes field default value. A crafted descriptor with a non-string default value for a bytes field could cause attacker-controlled code to be emitted into the generated conversion function. This vulnerability is fixed in 7.5.6 and 8.0.2.

Source published

13 May 2026 16:16:56 UTC

Source modified

11 Nov 2026 20:10:00 UTC

Saved here

12 Nov 2026 18:19:07 UTC

Source terms

NIST NVD usage terms; underlying source attribution retained

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Source: nvd · NIST NVD usage terms; underlying source attribution retained. The publisher's wording is preserved. ChangeIntel groups the information and labels changes. The JSON record includes additional source fields.

CVSS 4.0 · [email protected] · Secondary · 7.7 CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

CVSS 3.1 · [email protected] · Primary · 8.8 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS 3.1 · 0b0ca135-0b70-47e7-9f44-1890c2a1c46c · Secondary · 7.1 CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:L/A:H

## Summary protobufjs generated JavaScript for `toObject` conversion could include an unsafe expression derived from a schema-controlled `bytes` field default value. A crafted descriptor with a non-string default value for a `bytes` field could cause attacker-controlled code to be emitted into the generated conversion function. ## Impact An attacker who can provide or influence a protobuf descriptor may be able to execute arbitrary JavaScript in the context of the process using protobufjs. This requires the application to load an attacker-controlled schema or descriptor and then convert a message of the affected type with defaults enabled. Applications that only use trusted, application-defined schemas are not directly affected by this issue. ## Preconditions - The application must allow an attacker to control or influence a protobuf JSON descriptor or equivalent reflected schema. - The descriptor must define a `bytes` field with an attacker-controlled default value. - The application must call `toObject` with defaults enabled for the affected type. ## Workarounds Do not load protobuf schemas or JSON descriptors from untrusted sources with affected versions. If untrusted schemas must be accepted, validate or restrict field options before loading them and run schema processing in an isolated environment.

Source published

12 May 2026 15:06:13 UTC

Source modified

10 Sep 2026 03:50:45 UTC

Saved here

24 Oct 2026 13:17:17 UTC

Source terms

GitHub Advisory Database · CC-BY-4.0

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CVSS_V4 · CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Publisher rating · HIGH