# CVE-2026-101911: ip-address denial of service in Address6 constructor

Source: https://junglewise.ai/threats/cve-2026-101911-ip-address-is-a-library-for-parsing-and-manipulating-ipv4-and  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-28. Updated: 2026-09-28  
License: CC BY 4.0 with a link back

CVE-2026-101911 · Severity: medium · CVSS 4 · Published 2026-09-28

The ip-address library for JavaScript is vulnerable to denial of service when parsing oversized IPv6 address strings. An attacker who can pass a very large string (16+ MiB) to the Address6 constructor or validation function can cause the application to stall, consume excessive memory, or crash. The impact is limited in practice by common HTTP request size limits, but applications with custom parsing or higher limits are at risk.

Technologies: [Beaugunderson Ip-Address](https://junglewise.ai/threats/technologies/beaugunderson-ip-address), [ip-address (npm)](https://junglewise.ai/threats/technologies/ip-address). Vendors: [Beaugunderson](https://junglewise.ai/threats/vendors/beaugunderson), [npm](https://junglewise.ai/threats/vendors/npm).

## Quick answers

**Is CVE-2026-101911 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-101911 being exploited in the wild.

**How severe is CVE-2026-101911?** Medium severity, with a CVSS score of 4, published 28 September 2026.

**Which products and versions are affected?** Beaugunderson Ip-Address prior to 10.7.1; ip-address (npm) <= 10.7.0, SEMVER:introduced=0,fixed=10.7.1.

**Is there a fix for CVE-2026-101911?** Yes. ip-address (npm): upgrade to 10.7.1 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-101911 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-101911?** Check whether you run Beaugunderson Ip-Address or ip-address (npm) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- ip-address (npm): upgrade to 10.7.1 or later

  ```sh
  npm install ip-address@10.7.1
  ```


## Technical details

The Address6 constructor, Address6.isValid, and parse functions in src/ipv6.ts accept unbounded input strings and expand invalid characters through RE_BAD_CHARACTERS regex into large diagnostic strings via String.replace, consuming approximately 106 bytes per input byte. At 16 MiB, V8's maximum string length is exceeded, throwing a RangeError; at 32 MiB, the Node.js process is terminated. The vulnerability requires an attacker to supply a very large attacker-controlled field to the parsing functions without prior length validation; common HTTP constraints and body-parser defaults typically mitigate the risk.

## Affected products

- beaugunderson ip-address prior to 10.7.1

## Identifiers

- CVE-2026-101911
- GHSA-h3mg-xc3c-68pw

## Timeline

- 2026-09-28: disclosed

## References

- [https://github.com/beaugunderson/ip-address/commit/469ead1231b4cc059f2150c626e1e0c2895c0134](https://github.com/beaugunderson/ip-address/commit/469ead1231b4cc059f2150c626e1e0c2895c0134)
- [https://github.com/beaugunderson/ip-address/commit/8b34a21e0839b37c094066816fb2c2c48a2adcf5](https://github.com/beaugunderson/ip-address/commit/8b34a21e0839b37c094066816fb2c2c48a2adcf5)

## Related threats

- [ip-address Address6 regex denial of service](https://junglewise.ai/threats/duplicate-advisory-ip-address-address6-matches-a-zone-identifier-in-9feed89f)
- [ip-address Address6 quadratic regex denial of service](https://junglewise.ai/threats/cve-2026-111997-ip-address-before-10-7-4-allows-a-denial-of-service-cpu)
- [ip-address Address6 isLinkLocal incomplete subnet check](https://junglewise.ai/threats/cve-2026-101913-ip-address-is-a-library-for-parsing-and-manipulating-ipv4-and)
- [ip-address logic error in subnet containment check](https://junglewise.ai/threats/cve-2026-101912-ip-address-is-a-library-for-parsing-and-manipulating-ipv4-and)
- [ip-address library Address6 trust boundary bypass via NAT64 range](https://junglewise.ai/threats/cve-2026-101910-ip-address-is-a-library-for-parsing-and-manipulating-ipv4-and)