CVE-2025-27789

Inefficient RexExp complexity in generated code with .replace when transpiling named capturing groups

Published Mar 11, 2025 CVSS 3.1 · 6.2 Medium EPSS < 1% KEV · Not listed
Description
Babel is a compiler for writing next generation JavaScript. When using versions of Babel prior to 7.26.10 and 8.0.0-alpha.17 to compile regular expression named capturing groups, Babel will generate a polyfill for the `.replace` method that has quadratic complexity on some specific replacement pattern strings (i.e. the second argument passed to `.replace`). Generated code is vulnerable if all the following conditions are true: Using Babel to compile regular expression named capturing groups, using the `.replace` method on a regular expression that contains named capturing groups, and the code using untrusted strings as the second argument of `.replace`. This problem has been fixed in `@babel/helpers` and `@babel/runtime` 7.26.10 and 8.0.0-alpha.17. It's likely that individual users do not directly depend on `@babel/helpers`, and instead depend on `@babel/core` (which itself depends on `@babel/helpers`). Upgrading to `@babel/core` 7.26.10 is not required, but it guarantees use of a new enough `@babel/helpers` version. Note that just updating Babel dependencies is not enough; one will also need to re-compile the code. No known workarounds are available.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
EUVD EUVD EUVD-2025-7806 Babel has inefficient RegExp complexity in generated code with .replace when transpiling named capturing groups
Github GHSA Github GHSA GHSA-968p-4wvh-cqc8 Babel has inefficient RegExp complexity in generated code with .replace when transpiling named capturing groups
History
Type Values Removed Values Added
Metrics epss

{'score': 0.00035}

epss

{'score': 0.00043}

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description Babel is a compiler for writing next generation JavaScript. When using versions of Babel prior to 7.26.10 and 8.0.0-alpha.17 to compile regular expression named capturing groups, Babel will generate a polyfill for the `.replace` method that has quadratic complexity on some specific replacement pattern strings (i.e. the second argument passed to `.replace`). Generated code is vulnerable if all the following conditions are true: Using Babel to compile regular expression named capturing groups, using the `.replace` method on a regular expression that contains named capturing groups, and the code using untrusted strings as the second argument of `.replace`. This problem has been fixed in `@babel/helpers` and `@babel/runtime` 7.26.10 and 8.0.0-alpha.17. It's likely that individual users do not directly depend on `@babel/helpers`, and instead depend on `@babel/core` (which itself depends on `@babel/helpers`). Upgrading to `@babel/core` 7.26.10 is not required, but it guarantees use of a new enough `@babel/helpers` version. Note that just updating Babel dependencies is not enough; one will also need to re-compile the code. No known workarounds are available.
Title Inefficient RexExp complexity in generated code with .replace when transpiling named capturing groups
Weaknesses CWE-1333
References
Metrics cvssV3_1

{'score': 6.2, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

Subscriptions

No data.

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Mar 11, 2025, 7:53 PM
Reserved
Mar 6, 2025, 6:06 PM
Status
Deferred
Published
Mar 11, 2025, 8:15 PM
Modified
Jun 17, 2026, 9:04 AM