# CVE-2026-101910: ip-address: no classifier recognizes the NAT64 local-use range 64:ff9b:1::/48, allowing SSRF and trust-boundary bypass

> Attackers can bypass network trust boundaries in applications using this library if NAT64 local-use ranges are configured, potentially accessing internal resources.

- **Severity:** Medium 6.9 (`CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:H/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 28 Sep 2026
- **Updated:** 28 Sep 2026
- **Also known as:** CLEANSTART-2026-BJ83966, CLEANSTART-2026-ED95954, CLEANSTART-2026-PU19584, DEBIAN-CVE-2026-101910, ECHO-5e25-ee30-5fe8, GHSA-2vr4-cq9g-pvrc, MINI-32jg-qcvq-fmf4, MINI-3c27-2rj7-wxg5, MINI-4cf4-x853-cf9w, MINI-533f-3hqc-pj9c, MINI-86x6-c48w-pmp9, MINI-892w-v442-jp25, MINI-92j3-3vhm-wfhp, MINI-9cjp-f457-52rp, MINI-gfvf-c377-rqq2, MINI-h5qj-7g9h-v928, MINI-hrm4-xcc4-fqq7, MINI-hxqm-46cc-x52c, MINI-mvv3-6wwm-cxrv, MINI-pv83-r5g9-j35x, MINI-r3pg-9vpc-vq9c, UBUNTU-CVE-2026-101910

## What is CVE-2026-101910?

CVE-2026-101910 is a medium-severity server-side request forgery vulnerability in beaugunderson ip-address, published on 28 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

ip-address is a library for parsing and manipulating IPv4 and IPv6 addresses in JavaScript. From 10.2.0 until 10.5.1, the Address6 isPrivate classifier in src/ipv6.ts does not recognize the NAT64 local-use range 64:ff9b:1::/48. Applications that combine isPrivate, isLoopback, and isLinkLocal for a trust-boundary decision can treat an internal IPv4 destination encoded through that range as external. Exploitation depends on a server network using an operator-selected NAT64 prefix within the local-use range. A successful bypass can cross the intended network trust boundary. This issue is fixed in version 10.5.1.

Weakness: CWE-918 (Server-Side Request Forgery)

## Which versions are affected by CVE-2026-101910?

2 open source packages ship an affected version, including ip-address.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `ip-address` | npm | From 10.2.0 | 10.5.1 |
| `ip-address` | npm | From 10.2.0 | 10.5.1 |

## How do I fix CVE-2026-101910?

Upgrade ip-address to 10.5.1 or later.

## Is CVE-2026-101910 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-101910 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-101910 and fix it if it is affected.

What it is: CVE-2026-101910 is a medium-severity server-side request forgery vulnerability in beaugunderson ip-address, published on 28 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-101910 exists.

Affected packages and fixed versions:
- ip-address (npm): affected from 10.2.0; fixed in 10.5.1
- ip-address (npm): affected from 10.2.0; fixed in 10.5.1

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-101910/ (Markdown: https://insights.sbomify.com/CVE-2026-101910/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-101910
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-101910
- OSV: https://osv.dev/vulnerability/CVE-2026-101910

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-101910/
Summaries are generated and may contain mistakes; the official description above is the record.