CVE-2026-101899 — Axios: CIDR-form NO_PROXY entries are ignored, causing proxy exclusion bypass for internal IP ranges
Axios is a promise-based HTTP client for the browser and Node.js. From 1.15.0 until 1.20.0, Axios shouldBypassProxy treats the NO_PROXY CIDR form as a textual hostname suffix instead of evaluating the network range. A request targets an address covered by a CIDR entry in NO_PROXY while a proxy is configured. The CIDR bypass rule is not matched, so the request is sent through the configured proxy. For plaintext HTTP, the proxy can observe and modify URLs, headers, and bodies; for HTTPS, it can observe connection metadata and CONNECT requests. This issue is fixed in version 1.20.0.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.5% (30-day exploitation probability)+6
- Technical severity (medium)+3
- CISA SSVC: exploitation "poc"+5
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
CISA SSVC assessment CISA
Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
- Npm Axios: fixed in version 1.20.0 — github.com (GitHub Security Advisories)
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Axios Axios, Npm Axios).
- The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
- Apply the fixed version or the patch documented under Remediation.
- Search available logs for exploit probes, errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 6.9 | CVSS 4.0 | Medium | — | — | security-advisories@github.com via NIST National Vulnerability Database |
| 6.9 | CVSS 4.0 | Medium | — | — | GitHub_M via CVE Program (cve.org) e CISA ADP |
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X (score shown at the top: security-advisories@github.com) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
Timeline
What happened to this CVE, newest first.
- 2026
- Fix documented
- Affected products added · npm/axios
- SSVC assessment updated
- Affected products added · axios/axios
- Record published
- CVSS changed · 6.9
- Source status changed · → Received
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× References added · Oct 14, 2026 – Oct 14, 2026
- 1× Official description updated · Oct 13, 2026 – Oct 13, 2026
References
5 on the record
Elsewhere on this site
Related CVEs (same products)
- High CVE-2026-67321 Uncontrolled Recursion in Axios Aug 1, 2026
- Low CVE-2026-67319 Prototype Pollution in Axios Aug 1, 2026
- High CVE-2026-67320 Exposure of Sensitive Information in Axios Aug 1, 2026
- High CVE-2026-67312 Uncontrolled Resource Consumption in Axios Aug 1, 2026
- High CVE-2026-67315 axios versions 0.31.0 before 0.33.0 and 1.15.0 before 1.18.0 fail to recognize 0.0.0.0… Aug 1, 2026
- Medium CVE-2026-67314 Prototype Pollution in Axios Aug 1, 2026
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-101899 is "Axios: CIDR-form NO_PROXY entries are ignored, causing proxy exclusion bypass for internal IP ranges", rated Medium. It affects Axios (Axios); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 6.9 describes technical severity. EPSS 0.53% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
Comments
Moderated technical discussion. Read the community guidelines.
No comments yet.
Sign in or create an account to comment and suggest corrections.