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Fencer Intel
high 8.7

CVE-2026-89418 json

Uncontrolled Recursion leading to Denial of Service in protobuf-javascript (google-protobuf)

published last mo. modified last mo. also EUVD-2026-81523 , GHSA-5h29-r2cp-hfmr

Unreviewed: the maintainers' own advisory

Published by the maintainers on their GitHub repository protocolbuffers/protobuf-javascript. GitHub has not reviewed it into the GitHub Advisory Database, so the affected packages and versions are the maintainers' word. Read the full advisory on GitHub.

cvss
8.7
version 4.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 20%
public exploits
0
none known

Summary

google-protobuf contains an unbounded recursion when parsing unknown protobuf group fields. An attacker can send a small crafted payload of deeply nested START_GROUP wire bytes to any Node.js service that calls the generated deserializeBinary() API, causing a RangeError: Maximum call stack size exceeded and crashing the process. No authentication or prior knowledge of the schema is required.

Patch / fix

  • npm google-protobuf 4.0.3

Is CVE-2026-89418 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

Check with Fencer

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-89418 updated cvss 7.5

google-protobuf: google-protobuf: Denial of Service via uncontrolled recursion in protobuf group field parsing

  • Red Hat OpenShift AI (RHOAI) rhoai/odh-core-bff-rhel9, rhoai/odh-mod-arch-maas-rhel9, rhoai/odh-mod-arch-automl-rhel9, rhoai/odh-mod-arch-gen-ai-rhel9, rhoai/odh-mod-arch-mlflow-rhel9, rhoai/odh-mod-arch-autorag-rhel9, +3 more
    affected: workaround, no fix available
  • Red Hat OpenShift AI 2.25 rhoai/odh-dashboard-rhel9 1791853525, rhoai/odh-mod-arch-model-registry-rhel9 1791853432
    fixed: vendor fix RHSA-2026:87410
  • Red Hat OpenShift AI 2.25 rhoai/odh-rhel9-operator 1792570619, rhoai/odh-vllm-cpu-rhel9 1792018436, rhoai/odh-modelmesh-rhel9 1790881700, rhoai/odh-operator-bundle 1792571069, rhoai/odh-vllm-cuda-rhel9 1791358976, rhoai/odh-vllm-rocm-rhel9 1791282503, +64 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
Proof of concept is public
Automatable
yes
Technical impact
partial
Assessed
last mo.

Exploit prediction

0.28% chance of exploitation in the next 30 days, higher than 20% of all scored CVEs (FIRST EPSS, 2026-11-11).

Exploits and checks

  • github.com https://github.com/protocolbuffers/protobuf-javascript/security/advisories/GHSA-5h29-r2cp-hfmr referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 4.0 8.7 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
CNA 4.0 8.7 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/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

Affected packages

ecosystem package affected fixed in
npm google-protobuf
<=4.0.2
4.0.3

Affected products

  • Google protobuf-javascript (aka google-protobuf npm package)

Classification

Weakness

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

The maintainers of protocolbuffers/protobuf-javascript published their own advisory on GitHub. Reviewed sources take precedence over it.