Axios: ReDoS (O(N²)) in shouldBypassProxy host normalization, reachable via untrusted redirect Location — GHSA-MGHH-PGCX-3JJJ

Summary

## Summary Axios `shouldBypassProxy()` normalizes hostnames with `hostname.replace(/\.+$/, '')`. For a hostname shaped as many dots followed by a non-dot, the anchored regex can perform quadratic backtracking. Because axios re-evaluates proxy bypass rules for redirected requests, a malicious server can trigger this synchronous work through a crafted redirect `Location`. The issue affects Node.js applications that…

Timeline

Published by source

2026-09-30

Risk context

• Reported severity or threat level: high.
• Reported CVSS score: 8.2 out of 10.
• Reported EPSS value: 0.00402.
• Review exposure for the affected product or family: npm: axios.

Product

npm: axios

What to do

General, cautious steps (verify details in the official source):

• Prioritize patching or mitigation immediately (treat as actively risky).
• Identify affected product versions in your inventory and verify whether you are impacted.
• Apply vendor patches/updates or recommended mitigations as soon as available.
• Read the official advisory for exact affected versions and remediation steps.

Official advisory

• Read the official source
• CVE Record
• NVD

Evidence and provenance

Canonical advisory ID

GHSA-MGHH-PGCX-3JJJ

Source

GitHub

Vendor

GitHub

Published by source

2026-09-30

Last source activity

2026-09-30

Additional identifiers

CVE-2026-101906

Curated by

hlukh.ch

Related advisories and connections

These advisories are connected by shared CVE, product, vendor, source, or time signals.