Vulnerability in ip-address (CVE-2026-101912)
Summary
Vulnerability in ip-address (CVE-2026-101912). Risk of unauthorized operations or information disclosure. Exploitable via Address4. Mitigation: upgrade to 10.7.1 or later.
Original description
The description as published by the source.
Summary
isInSubnet() and isHostInSubnet() accept an address of either family and compare masked binary strings without checking that both operands are the same family. Address4 pads to 32 bits and Address6 to 128, so whenever the leading bits agree the strings are equal: new Address6('a00::1').isInSubnet(new Address4('10.0.0.0/8')) is true, and new Address4('32.0.0.1').isInSubnet(new Address6('2000::/3')) is true. No IPv4 address is inside an IPv6 network, so both answers are untrue.
An application that parses untrusted input as whichever family accepts it and then tests the result against a fixed-family allowlist can admit an address outside the list.
Details
Both methods are in src/common.ts:
export function isInSubnet(this: Address4 | Address6, address: Address4 | Address6) {
if (this.subnetMask < address.subnetMask) {
return false;
}
return isHostInSubnet.call(this, address);
}
export function isHostInSubnet(this: Address4 | Address6, address: Address4 | Address6) {
return this.mask(address.subnetMask) === address.mask();
}
mask(n) returns the first n bits of the address as a string of 0 and 1, taken from a representation padded to the family's width. new Address6('a00::1').mask(8) is '00001010', and so is new Address4('10.0.0.0/8').mask(), so string equality reports containment. The signature admits either family on either side, so TypeScript raises nothing, and the v4 property on Address6 marks IP…
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-2026-101912 has been found in ip-address.
Attackers can target a specific entry point like Address4 over the network to misuse the product.
Risk of unauthorized operations or information disclosure.
What to do: upgrade ip-address to 10.7.1 or later.
If unsure, ask your IT team or search "ip-address CVE-2026-101912" on the vendor's site.
CVE-2026-101912 (ip-address) — CWE-697
Attack surface: Address4 / Address6 / true / false
Patched: 10.7.1 — 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-697) exists in ip-address. Attackers reach the vulnerable code path via Address4.
Check the vendor advisory for the affected versions of ip-address. Attack surface: Address4 / Address6 / true / false.
Severity: ?. Risk of unauthorized operations or information disclosure.
Update to 10.7.1.
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 'ip-address' . 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 'ip-address' . | 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
ip-address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 ip-address to 10.7.1ステージング環境で 10.7.1 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 nvd.nist.gov
- web github.com