PatchSiren cyber security CVE debrief
CVE-2026-44293 Protobufjs Project CVE debrief
CVE-2026-44293 is a vulnerability in Protobufjs, a JavaScript library for working with Protocol Buffers. The vulnerability allows for attacker-controlled code to be emitted into the generated conversion function. This is due to an unsafe expression derived from a schema-controlled bytes field default value in the generated JavaScript for toObject conversion. A crafted descriptor with a non-string default value for a bytes field could cause this vulnerability. The vulnerability is fixed in versions 7.5.6 and 8.0.2 of Protobufjs.
- Vendor
- Protobufjs Project
- Product
- Protobufjs
- CVSS
- HIGH 7.7
- CISA KEV
- Not listed in stored evidence
- Original CVE published
- 2026-05-13
- Original CVE updated
- 2026-09-09
- Advisory published
- 2026-05-13
- Advisory updated
- 2026-09-09
Who should care
Developers and users of Protobufjs, especially those using versions prior to 7.5.6 and 8.0.2, should be aware of this vulnerability. This vulnerability could allow attackers to execute arbitrary code, potentially leading to security breaches. Users of Red Hat products that utilize Protobufjs may also be affected, as indicated by the presence of Red Hat errata references.
Technical summary
The vulnerability in Protobufjs arises from the generation of JavaScript code for toObject conversion. Specifically, the code generated for handling bytes fields with default values could include unsafe expressions. An attacker could craft a descriptor with a non-string default value for a bytes field, leading to the emission of attacker-controlled code in the generated conversion function. This issue has been addressed in Protobufjs versions 7.5.6 and 8.0.2. The CVSS score for this vulnerability is 7.7, indicating a high severity level.
Defensive priority
High priority should be given to updating Protobufjs to versions 7.5.6 or 8.0.2, or later, to mitigate this vulnerability. Additionally, developers should review their code for any usage of crafted descriptors that could potentially exploit this vulnerability.
Recommended defensive actions
- Update Protobufjs to version 7.5.6 or 8.0.2, or later.
- Review code for usage of crafted descriptors.
- Monitor for any suspicious activity related to Protobufjs usage.
- Apply Red Hat errata if applicable.
- Consider implementing additional security measures to detect and prevent code injection attacks.
Evidence notes
The CVE record and NVD detail provide information on the vulnerability, including its description, CVSS score, and affected versions. The source item URL provides additional context from the NVD database. The mitigation or vendor reference from GitHub provides information on the fix for this vulnerability.
Sources and references
Verified primary and authoritative sources
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CVE-2026-44293 CVE Program record
Publisher, destination, and source semantics verified
URL: https://www.cve.org/CVERecord?id=CVE-2026-44293
CVE Program - Official CVE Program record with source-provided CVE metadata.
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CVE-2026-44293 NVD vulnerability detail
Publisher, destination, and source semantics verified
URL: https://nvd.nist.gov/vuln/detail/CVE-2026-44293
NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.
Supplemental references
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Mitigation or vendor reference
Unverified legacy reference
URL: https://github.com/protobufjs/protobuf.js/security/advisories/GHSA-66ff-xgx4-vchm
[email protected] - Mitigation, Vendor Advisory
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Source reference
Unverified legacy reference
URL: https://access.redhat.com/errata/RHSA-2026:26090
0b0ca135-0b70-47e7-9f44-1890c2a1c46c
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Source reference
Unverified legacy reference
URL: https://access.redhat.com/errata/RHSA-2026:26234
0b0ca135-0b70-47e7-9f44-1890c2a1c46c
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Source reference
Unverified legacy reference
URL: https://access.redhat.com/errata/RHSA-2026:29795
0b0ca135-0b70-47e7-9f44-1890c2a1c46c
-
Source reference
Unverified legacy reference
URL: https://access.redhat.com/security/cve/CVE-2026-44293
0b0ca135-0b70-47e7-9f44-1890c2a1c46c
-
Source reference
Unverified legacy reference
URL: https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-44293.json
0b0ca135-0b70-47e7-9f44-1890c2a1c46c
Methodology and review provenance
AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.