Description
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.
Affected products
protobufjs_project: protobufjs
References10
- github.com/protobufjs/protobuf.js/security/advisories/GHSA-66ff… MitigationVendor Advisory
- access.redhat.com/errata/RHSA-2026:26090
- access.redhat.com/errata/RHSA-2026:26234
- access.redhat.com/errata/RHSA-2026:29795
- access.redhat.com/errata/RHSA-2026:34160
- access.redhat.com/errata/RHSA-2026:34374
- access.redhat.com/errata/RHSA-2026:37186
- access.redhat.com/errata/RHSA-2026:37385
- access.redhat.com/errata/RHSA-2026:37628
- access.redhat.com/errata/RHSA-2026:54555
Metrics
- CVSS 3.1
-
8.8
HIGH
Score source: NVD
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - CVSS 4.0
-
7.7
HIGH
Score source: CNA
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 - EPSS — exploit probability
- 0% percentile: 36 · as of 14 November 2026
- CWE
- CWE-94
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.