LiveActive security incident?Get immediate response
CVE Record

CVE-2026-44293: protobufjs: Code injection through bytes field defaults in generated toObject code

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.

HighCVSS 7.7Not KEV-listedUpdated
Discuss exposureBack to CVEs
Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

protobufjs can turn protobuf schemas into JavaScript. In vulnerable versions, a malicious schema can cause code to be inserted into generated conversion logic. The main business risk is compromise of services that process protobuf definitions or descriptors from users, partners, plugins, or other semi-trusted sources.

Executive priority

Treat as high priority for internet-facing or multi-tenant systems that process external protobuf schemas. For systems using only trusted, static schemas, schedule prompt dependency remediation and verify no untrusted descriptor path exists.

Technical view

Before 7.5.6 and 8.0.2, protobufjs generated toObject code using an unsafe expression derived from a schema-controlled bytes field default. A crafted descriptor with a non-string bytes default could emit attacker-controlled JavaScript. The issue is CWE-94 with CVSS 4.0 score 7.7 high.

Likely exposure

Exposure is most likely in Node.js applications, tooling, or services using protobuf.js <7.5.6 or 8.0.0-8.0.1 that compile or load protobuf descriptors from less-trusted sources. Static, vendor-controlled schemas reduce practical exploitability but do not remove upgrade urgency.

Exploitation context

The bundle says KEV is false and provides no evidence of active exploitation. Exploitation requires some ability to provide or influence a crafted protobuf descriptor or schema default, but no user interaction is indicated in the CVSS vector.

Researcher notes

Key validation question is schema control. The vulnerability is in generated toObject conversion code, not ordinary protobuf message parsing alone. Evidence in the bundle names fixed versions, CVSS, CWE-94, Red Hat tracking, and no KEV status.

Mitigation direction

  • Upgrade protobuf.js to 7.5.6 or 8.0.2 or later.
  • Review vendor advisories for affected downstream packages or platforms.
  • Restrict protobuf descriptor ingestion to trusted sources where possible.
  • Audit build and runtime paths that compile protobuf definitions.
  • Prioritize services processing user-supplied or partner-supplied schemas.

Validation and detection

  • Inventory direct and transitive protobufjs dependencies.
  • Check deployed versions against <7.5.6 and 8.0.0-8.0.1.
  • Identify code paths that load or compile external protobuf descriptors.
  • Confirm patched versions are present in lockfiles and production images.
  • Review Red Hat errata if using affected Red Hat packages.
Prepared
Confidence
high
Sources
12

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

cwe · medium confidence lookup

CWE-94: Code execution behavior lookup

Code execution and unsafe deserialization weaknesses often justify reviewing execution behavior and process telemetry. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.

Open ATT&CK lookup
cve · low confidence lookup

CVE-2026-44293 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

Open ATT&CK lookup
Vulnerability profileCVE Program record
Severity
High
CVSS
7.7 (4.0)
Known Exploited
No
Published

Vector: 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

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

2CVSS vectors
5Timeline events
2ADP providers
13Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: noneAutomatable: noTechnical Impact: total

CVSS vector scores

2 official scores

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
7.7CVSS 4.0HighCVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N——GitHub_M
7.1CVSS 3.1HighCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:L/A:H1.65.5redhat-SADP

Vulnerability scoring details

Base CVSS 4.0 score

7.7High
CVSS 4.0 vector shape for CVE-2026-44293Attack VectorAttack ComplexityAttack RequirementsPrivileges RequiredUser InteractionVS ConfidentialityVS IntegrityVS AvailabilitySS ConfidentialitySS IntegritySS Availability

Vector: 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

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Attack Requirements
NonePresent
Privileges Required
NoneLowHigh
User Interaction
NonePassiveActive
VS Confidentiality
HighLowNone
VS Integrity
HighLowNone
VS Availability
HighLowNone
SS Confidentiality
HighLowNone
SS Integrity
HighLowNone
SS Availability
HighLowNone

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. ADP timelineredhat-SADP

    Made public.

  3. CVE publishedCVE Program

    The CVE record was published.

  4. ADP timelineredhat-SADP

    Reported to Red Hat.

  5. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CISA-ADPCISA ADP Vulnrichment
other:ssvc
redhat-SADPprotobufjs: protobufjs: Arbitrary code execution due to unsafe expression generation from crafted protobuf descriptors
other:Red Hat severity ratingcvssV3_1
  • 2026-05-13T16:03:50.961Z: Reported to Red Hat.
  • 2026-05-13T14:43:33.342Z: Made public.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
protobufjsprotobuf.js< 7.5.6, >= 8.0.0, < 8.0.2Listed
Weakness

CWE details

CWE-94

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.

CWE-94 · source CWE mapping

Improper Control of Generation of Code ('Code Injection')

Improper Control of Generation of Code ('Code Injection') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

Open CWE intelligenceSame-CWE CVEs