How severe is GHSA-29mw-wpgm-hmr9?

GHSA-29mw-wpgm-hmr9 has a CVSS score of 5.3/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by GHSA-29mw-wpgm-hmr9?

GHSA-29mw-wpgm-hmr9 affects the following packages: lodash (npm), lodash-es (npm), lodash.trimend (npm), lodash.trim (npm), lodash-rails (RubyGems). Ecosystems affected: npm, RubyGems.

How do I fix GHSA-29mw-wpgm-hmr9?

Update lodash to version 4.17.21 or later. Run your dependency manager's update command and verify no transitive dependencies pin the vulnerable version. Use O3 Security's SCA scanner to confirm the fix is applied across your entire dependency tree.

Is GHSA-29mw-wpgm-hmr9 actively exploited in the wild?

Yes. There are 6 known exploit references for GHSA-29mw-wpgm-hmr9, including 6 in-the-wild exploitations observed on GitHub and other sources. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for GHSA-29mw-wpgm-hmr9?

GHSA-29mw-wpgm-hmr9 has an EPSS (Exploit Prediction Scoring System) score of 0.2%, placing it in the 48th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

📦 npm💎 RubyGems

GHSA-29mw-wpgm-hmr9

Q: Can O3 Security detect GHSA-29mw-wpgm-hmr9 in my codebase?

Yes. O3 Security's Impact-Aware SCA scanner identifies GHSA-29mw-wpgm-hmr9 across all affected ecosystems (npm, RubyGems), correlates it against your dependency graph, and uses function-level reachability to confirm whether the vulnerable code path is actually reachable in your application — eliminating false positives. You can scan your stack for GHSA-29mw-wpgm-hmr9 directly from the O3 platform.

MEDIUM

Regular Expression Denial of Service (ReDoS) in lodash

Also known asCVE-2020-28500

Published

Jan 6, 2022

Updated

Sep 29, 2025

Affected

5 pkgs

Patched

3 / 5

Exploits

6 known

EPSS Exploitation Probability

via FIRST.org ↗

0.2%probability of exploitation in next 30 days

Lower Risk48th percentile0.00%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Blast Radius

5 pkgs affected

📦lodash📦lodash-es📦lodash.trimend📦lodash.trim💎lodash-rails

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects npm packages — download data is not available via public APIs for these ecosystems.

Description

All versions of package lodash prior to 4.17.21 are vulnerable to Regular Expression Denial of Service (ReDoS) via the toNumber, trim and trimEnd functions.

Steps to reproduce (provided by reporter Liyuan Chen):

var lo = require('lodash');

function build_blank(n) {
    var ret = "1"
    for (var i = 0; i < n; i++) {
        ret += " "
    }
    return ret + "1";
}
var s = build_blank(50000) var time0 = Date.now();
lo.trim(s) 
var time_cost0 = Date.now() - time0;
console.log("time_cost0: " + time_cost0);
var time1 = Date.now();
lo.toNumber(s) var time_cost1 = Date.now() - time1;
console.log("time_cost1: " + time_cost1);
var time2 = Date.now();
lo.trimEnd(s);
var time_cost2 = Date.now() - time2;
console.log("time_cost2: " + time_cost2);

Affected Packages

5 total 3 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`lodash`	≥ 4.0.0&&< 4.17.21	4.17.21
📦npm	`lodash-es`	≥ 4.0.0&&< 4.17.21	4.17.21
📦npm	`lodash.trimend`	≥ 4.0.0	No fix
📦npm	`lodash.trim`	≥ 4.0.0	No fix
💎RubyGems	`lodash-rails`	≥ 4.0.0&&< 4.17.21	4.17.21

Exploits & PoCs

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.