ip-address: Address6 matches a zone identifier in quadratic time ahead of its length limit, allowing a single long string to stall 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-2026-111997: 0.32% estimated exploitation activity in the next 30 days; percentile 24.45 (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() strip a zone identifier with the pattern /%.$/ before they apply the 45-character length limit. When the string holds many % characters followed by a line terminator, the pattern is retried from every % and each attempt scans to the line terminator before failing, so rejecting the string takes time proportional to the square of its length. 10,000 % characters and a newline take 41 ms, 40,000 take 632 ms and 100,000 take 3.9 s of synchronous work. The same strings without the newline are rejected in under a millisecond. An application that validates an attacker-supplied string with these methods can be stalled by a single long request. The input is rejected with the correct AddressError; the cost of reaching that rejection is the defect. Details The constructor in src/ipv6.ts removes the CIDR suffix, then the zone, then checks the length of what is left: REZONESTRING is /%.$/. It has no anchor at its start, . does not match a line…

Published by the source

22 Oct 2026, 16:19 UTC

Last modified by the source

22 Oct 2026, 16:30 UTC

Source last checked

26 Oct 2026, 13:07 UTC

1. Revision 5 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-rxp7-6hxx-x8q5

2. Revision 4 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-rxp7-6hxx-x8q5

3. Revision 3 · amended · 25 Oct 2026

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

4. Revision 2 · amended · 24 Oct 2026

   Amended from osv record GHSA-rxp7-6hxx-x8q5

5. Revision 1 · created · 23 Oct 2026

   Published from ghsa record GHSA-rxp7-6hxx-x8q5

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# Patch Next advisory brief: CVE-2026-111997

Advisory: ip-address: Address6 matches a zone identifier in quadratic time ahead of its length limit, allowing a single long string to stall the process
IDs: CVE-2026-111997, GHSA-rxp7-6hxx-x8q5
Record: https://patchnext.com/advisories/cve-2026-111997 (revision 5, source checked 26 Oct 2026, 13:07 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 10.7.4. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm ip-address: affected <= 10.7.3; fixed in 10.7.4

## 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-rxp7-6hxx-x8q5 (GitHub-reviewed advisory GHSA-rxp7-6hxx-x8q5 lists affected ranges: npm ip-address >=0 <=10.7.3)
- Verified: https://osv.dev/vulnerability/GHSA-rxp7-6hxx-x8q5 (OSV record GHSA-rxp7-6hxx-x8q5 lists affected ranges: npm ip-address >=0 <10.7.4 (fixed))

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