ip-address: Address6 builds a parse diagnostic proportional to the input with no length bound, allowing a single long string to stall or crash the process

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

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 · score source

EPSS

• CVE-2026-101911: 0.38% estimated exploitation activity in the next 30 days; percentile 32.40 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary new Address6() and Address6.isValid() place no bound on the length of the string they parse. When the string contains a character that cannot appear in an IPv6 address, the parser builds a diagnostic that wraps every such character in a 34-byte <span class="parse-error", so the work and the memory scale with the input rather than with an address. A 1 MiB string of ! costs about 110 MB and 70 ms of synchronous work, 8 MiB costs about 800 MB and half a second, 16 MiB throws a RangeError in place of the documented AddressError, and 32 MiB aborts the Node process. isValid() builds the diagnostic and discards it, so a caller that only asks whether a string is valid pays the full price. An application that validates an attacker-supplied string with these methods can be stalled or crashed by a single oversized request. This is a crash on input that should have been rejected cleanly, which SECURITY.md lists as in scope. Details parse() in src/ipv6.ts checks for characters outside…

Published by the source

29 Sep 2026, 23:46 UTC

Last modified by the source

30 Sep 2026, 00:00 UTC

Source last checked

26 Oct 2026, 13:06 UTC

1. Revision 4 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-h3mg-xc3c-68pw

2. Revision 3 · amended · 24 Oct 2026

   Reviewed OSV alias/range/CVSS4 correction; package source scopes and original publication preserved. No customer finding resolved.

3. Revision 2 · amended · 24 Oct 2026

   Amended from osv record GHSA-h3mg-xc3c-68pw

4. Revision 1 · created · 23 Oct 2026

   Published from ghsa record GHSA-h3mg-xc3c-68pw

Preview the exact text before you copy it. Commands are read-only suggestions; review them before running anything.

# Patch Next advisory brief: CVE-2026-101911

Advisory: ip-address: Address6 builds a parse diagnostic proportional to the input with no length bound, allowing a single long string to stall or crash the process
IDs: CVE-2026-101911, GHSA-h3mg-xc3c-68pw
Record: https://patchnext.com/advisories/cve-2026-101911 (revision 4, source checked 26 Oct 2026, 13:06 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.3)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: ip-address 10.7.1. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm ip-address: affected <= 10.7.0; fixed in 10.7.1

## Suggested inspection (read-only)
- `npm ls ip-address --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on ip-address.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-h3mg-xc3c-68pw (GitHub-reviewed advisory GHSA-h3mg-xc3c-68pw lists affected ranges: npm ip-address >=0 <=10.7.0)
- Verified: https://osv.dev/vulnerability/GHSA-h3mg-xc3c-68pw (OSV record GHSA-h3mg-xc3c-68pw lists affected ranges: npm ip-address >=0 <10.7.1 (fixed))

Commands are suggestions: review each one before running it.