CVE-2025-27789CWE-1333

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

Medium · published March 11, 2025

CVSS v3.1
6.2
EPSS
1%
Percentile
46.1
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
6.2 · MEDIUM
Vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS v4.0
Not supplied
EPSS
0.00563 · 46.1th percentile
Weakness
CWE-1333 · Inefficient Regular Expression Complexity
Published
2025-03-11T19:09Z
EPSS history
Timeline
  • 11 MAR 19:09Z
    Inefficient RexExp complexity in generated code with .replace when transpiling named capturing groups
    cvelistv5