# CVE-2026-111997: ip-address: Address6 matches a zone identifier in quadratic time ahead of its length limit, allowing a single long string to stall the process

> An attacker can cause a denial of service by sending input with many percent characters to the Address6 constructor, leading to high CPU consumption.

- **Severity:** Medium 6.3 (`CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/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:** 18 Oct 2026
- **Updated:** 18 Oct 2026
- **Also known as:** CLEANSTART-2026-TS24569, CLSA-2026-1792486317, CLSA-2026-1792494889, CLSA-2026-1793097494, CLSA-2026-1793098694, CLSA-2026-1793111658, CLSA-2026-1793111838, CLSA-2026-1793180922, CLSA-2026-1793183882, CLSA-2026-1793187941, CLSA-2026-1793207110, DEBIAN-CVE-2026-111997, ECHO-c732-3b7c-69e0, GHSA-rxp7-6hxx-x8q5, MINI-663x-95j7-vvw3, MINI-9938-wrx4-v8g4, MINI-w23w-m4w7-v9jg, UBUNTU-CVE-2026-111997

## What is CVE-2026-111997?

CVE-2026-111997 is a medium-severity denial of service vulnerability in beaugunderson ip-address, published on 18 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

ip-address before 10.7.4 allows a denial of service (CPU consumption from quadratic complexity, and application stall) via many % characters in input reaching a function call that uses the Address6 constructor.

Weakness: CWE-1333 (Inefficient Regular Expression Complexity)

## Which versions are affected by CVE-2026-111997?

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


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `ip-address` | npm | All versions | 10.7.4 |
| `ip-address` | npm | All versions | 10.7.4 |

## How do I fix CVE-2026-111997?

Upgrade ip-address to 10.7.4 or later.

## Is CVE-2026-111997 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-111997 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-111997 and fix it if it is affected.

What it is: CVE-2026-111997 is a medium-severity denial of service vulnerability in beaugunderson ip-address, published on 18 Oct 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-2026-111997 exists.

Affected packages and fixed versions:
- ip-address (npm): affected all versions; fixed in 10.7.4
- ip-address (npm): affected all versions; fixed in 10.7.4

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-2026-111997/ (Markdown: https://insights.sbomify.com/CVE-2026-111997/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-111997
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-111997
- OSV: https://osv.dev/vulnerability/CVE-2026-111997

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-111997/
Summaries are generated and may contain mistakes; the official description above is the record.