How severe is CVE-2026-89418?

CVE-2026-89418 has a CVSS 4.0 base score of 8.7, rated high severity.

Is CVE-2026-89418 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (18th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2026-89418?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2026-89418 published?

CVE-2026-89418 was published on 2026-09-17 and last updated on 2026-09-18.

CVE-2026-89418

CVE-2026-89418 is a high-severity vulnerability with a CVSS 4.0 base score of 8.7. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-674.

Key facts

Severity: High (CVSS 4.0 base score 8.7)
EPSS exploit prediction: 0% (18th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-674
Published: 2026-09-17
Last modified: 2026-09-18

Description

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.

Frequently asked questions

What is CVE-2026-89418?: 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.
How severe is CVE-2026-89418?: CVE-2026-89418 has a CVSS 4.0 base score of 8.7, rated high severity.
Is CVE-2026-89418 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (18th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-89418?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2026-89418 published?: CVE-2026-89418 was published on 2026-09-17 and last updated on 2026-09-18.

References

https://github.com/protocolbuffers/protobuf-javascript/security/advisories/GHSA-5h29-r2cp-hfmr

Other CWE-674 (Uncontrolled Recursion) vulnerabilities

CVE-2026-43185 — Critical (CVSS 9.8): In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix signededness bug in…
CVE-2023-51803 — Critical (CVSS 9.8): LinuxServer.io Heimdall before 2.5.7 does not prevent use of icons that have non-image data such as the "<?php ?>"…
CVE-2021-41752 — Critical (CVSS 9.8): Stack overflow vulnerability in Jerryscript before commit e1ce7dd7271288be8c0c8136eea9107df73a8ce2 on Oct 20, 2021 due…
CVE-2018-1000618 — Critical (CVSS 9.8): EOSIO/eos eos version after commit f1545dd0ae2b77580c2236fdb70ae7138d2c7168 contains a stack overflow vulnerability in…
CVE-2025-10728 — Critical (CVSS 9.4): When the module renders a Svg file that contains a <pattern> element, it might end up rendering it recursively leading…
CVE-2026-32327 — Critical (CVSS 9.1): A bug in APR-util version 1.6.3 (and earlier) allows a stack recursion attack against any library consumer which parses…

Browse all CWE-674 (Uncontrolled Recursion) vulnerabilities →