Vulnerability in axios (CVE-2026-101906)
Summary
Vulnerability in axios (CVE-2026-101906). Risk of unauthorized operations or information disclosure. Exploitable via Location. Mitigation: upgrade to 1.20.0 or later.
Original description
The description as published by the source.
Summary
Axios shouldBypassProxy() normalizes hostnames with hostname.replace(/\.+$/, ''). For a hostname shaped as many dots followed by a non-dot, the anchored regex can perform quadratic backtracking. Because axios re-evaluates proxy bypass rules for redirected requests, a malicious server can trigger this synchronous work through a crafted redirect Location.
The issue affects Node.js applications that use environment proxy variables with NO_PROXY and allow redirects.
Impact
An attacker-controlled server can return a redirect whose hostname causes the axios process to spend significant CPU time in synchronous hostname normalization. During this time, the Node.js event loop is blocked and the application cannot handle other work on that thread.
This is an availability-only issue. It does not disclose request data or modify requests.
Affected Functionality
Affected:
- Node.js HTTP adapter.
- Environment proxy handling through
HTTP_PROXYorHTTPS_PROXY. NO_PROXYorno_proxyset to a non-empty value.- Redirects followed by axios or
follow-redirects.
Not affected:
- Browser adapters.
- Requests with
proxy: false. - Requests with no
NO_PROXYvalue. - Requests with
maxRedirects: 0, unless application code manually follows the malicious redirect and re-enters axios.
Technical Details
lib/helpers/shouldBypassProxy.js contains:
return unmapIPv4MappedIPv6(hostname.replace(/\.+$/, ''));
When the hostname is `"." * n + "a"…
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-101906 has been found in axios.
Attackers can target a specific entry point like Location over the network to misuse the product.
Risk of unauthorized operations or information disclosure.
What to do: upgrade axios to 1.20.0 or later.
If unsure, ask your IT team or search "axios CVE-2026-101906" on the vendor's site.
CVE-2026-101906 (axios) — CWE-400
Attack surface: Location / NO_PROXY / HTTP_PROXY / HTTPS_PROXY
Patched: 1.20.0 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-400) exists in axios. Attackers reach the vulnerable code path via Location.
Check the vendor advisory for the affected versions of axios. Attack surface: Location / NO_PROXY / HTTP_PROXY / HTTPS_PROXY.
Severity: ?. Risk of unauthorized operations or information disclosure.
Update to 1.20.0.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'axios' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'axios' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
axiosを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade axios to 1.20.0ステージング環境で 1.20.0 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
-
3Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
References
- web github.com
- web github.com
- web github.com
- web github.com
- web nvd.nist.gov
- web github.com