GHSA-257v-vj4p-3w2h is a medium-severity (CVSS 5.3) CWE-770 vulnerability in color-string. 1 public exploit reference exists, so weaponization risk is real. O3 Security confirms whether GHSA-257v-vj4p-3w2h is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Regular Expression Denial of Service (ReDOS)
Real-World Exposure
color-stringReal-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
In the npm package color-string, there is a ReDos (Regular Expression Denial of Service) vulnerability regarding an exponential time complexity for
linearly increasing input lengths for hwb() color strings.
Strings reaching more than 5000 characters would see several milliseconds of processing time; strings reaching more than 50,000 characters began seeing 1500ms (1.5s) of processing time.
The cause was due to a the regular expression that parses hwb() strings - specifically, the hue value - where the integer portion of the hue value used a 0-or-more quantifier shortly thereafter followed by a 1-or-more quantifier.
This caused excessive backtracking and a cartesian scan, resulting in exponential time complexity given a linear increase in input length.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | color-string | all versions | 1.5.5 |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for color-string. 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 color-string to 1.5.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-257v-vj4p-3w2h 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-257v-vj4p-3w2h 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-257v-vj4p-3w2h. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-257v-vj4p-3w2h in your dependencies?
O3 detects GHSA-257v-vj4p-3w2h across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.