CVE-2026-71430: node-re2: String.prototype.replace(re2, template) aborts the Node process (uncatchable ToLocalChecked on empty MaybeLocal) when the result exceeds V8's max string length

Vulnerability summary

CVE-2026-71430 is a medium (CVSS 6.2) Reachable Assertion vulnerability in uhop node-re2. EPSS estimates a 0.16% chance of exploitation in the next 30 days, higher than 4.9% of scored vulnerabilities.

Timeline

1. 06-08-2026
   PublishedVulnerability first disclosed.
2. 07-08-2026
   Last modifiedVulnerability information updated.

Description

node-re2 provides RE2 regular expression bindings for Node.js. Prior to version 1.25.1, the WrappedRE2::Replace function built its replacement result and passed it to V8 using ToLocalChecked without checking for the empty MaybeLocal that V8 returns when the resulting string or buffer exceeds V8's maximum string length. When a global replace uses an output amplifying replacement template, the result can grow quadratically with the input size, and once the result exceeds V8's maximum string length, the unchecked ToLocalChecked call causes a fatal, uncatchable process abort instead of a catchable exception. This issue is fixed in version 1.25.1.

• CWE-617Reachable AssertionThe product contains an assert() or similar statement that can be triggered by an attacker, which leads to an application exit or other behavior that is more severe than necessary.