# CVE-2026-10822: ISC BIND assertion failure via malformed PRIVATEDNS record

Source: https://junglewise.ai/threats/cve-2026-10822-isc-bind-assertion-failure-via-malformed-privatedns-record  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-07-22. Updated: 2026-07-22  
License: CC BY 4.0 with a link back

CVE-2026-10822 · Severity: medium · CVSS 6.5 · Published 2026-07-22

BIND is a widely used software suite for managing the Domain Name System (DNS), which translates human-readable web addresses into IP addresses. A vulnerability has been identified where processing a specially crafted, invalid DNS record can cause the BIND server to crash. This could lead to a denial-of-service, preventing users from accessing websites or services that rely on the affected DNS server.

Technologies: [Isc BIND 9](https://junglewise.ai/threats/technologies/bind-9). Vendors: [Isc](https://junglewise.ai/threats/vendors/isc).

## Quick answers

**Is CVE-2026-10822 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-10822 being exploited in the wild.

**How severe is CVE-2026-10822?** Medium severity, with a CVSS score of 6.5, published 22 July 2026.

**Which products and versions are affected?** Isc BIND 9 9.18.0 through 9.18.50, 9.20.0 through 9.20.24, 9.21.0 through 9.21.23, 9.18.11-S1 through 9.18.50-S1, 9.20.9-S1 through 9.20.24-S1.

**Is there a fix for CVE-2026-10822?** A patch was published on 2026-07-22: Patched versions 9.20.26 and 9.21.24 released Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-10822 attacked?** It is attacked over the network, in a hosted service.

**Am I affected by CVE-2026-10822?** Check whether you run Isc BIND 9 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.

## Technical details

A vulnerability exists in BIND 9's handling of DNS records (such as KEY or DNSKEY) that utilize the PRIVATEDNS algorithm (253). The flaw is triggered when a record contains an algorithm identifier with a length field that exceeds the actual data provided. While BIND initially accepts and stores this malformed record, a subsequent attempt to render the record to text causes a consistency check failure (assertion failure). This results in the BIND process aborting and exiting. The issue is reachable remotely if the server is configured to process or display such records. Patches are available in versions 9.20.26 and 9.21.24.

## Affected products

- ISC BIND 9 9.18.0 through 9.18.50, 9.20.0 through 9.20.24, 9.21.0 through 9.21.23, 9.18.11-S1 through 9.18.50-S1, 9.20.9-S1 through 9.20.24-S1

## Timeline

- 2026-07-15: other: Early notification issued
- 2026-07-22: disclosed: Public disclosure of the vulnerability
- 2026-07-22: patched: Patched versions 9.20.26 and 9.21.24 released

## References

- [https://downloads.isc.org/isc/bind9/9.20.26](https://downloads.isc.org/isc/bind9/9.20.26)
- [https://downloads.isc.org/isc/bind9/9.21.24](https://downloads.isc.org/isc/bind9/9.21.24)
- [https://kb.isc.org/docs/cve-2026-10822](https://kb.isc.org/docs/cve-2026-10822)

## Related threats

- [ISC BIND recursive server assert failure denial of service](https://junglewise.ai/threats/cve-2026-97313-a-recursive-bind-server-that-receives-a-query-with-recursion)
- [ISC BIND DNSSEC validation bypass in NSEC records](https://junglewise.ai/threats/cve-2026-13321-isc-bind-dnssec-validation-bypass-in-nsec-records)
- [ISC BIND 9 denial of service via NSEC and NSEC3 assertion failure](https://junglewise.ai/threats/cve-2026-13204-isc-bind-9-denial-of-service-via-nsec-and-nsec3-assertion-failure)
- [ISC BIND 9 denial of service via CNAME or DNAME record ordering](https://junglewise.ai/threats/cve-2026-12617-isc-bind-9-denial-of-service-via-cname-or-dname-record-ordering)
- [ISC BIND 9 cache poisoning via RRSIG label count discrepancy](https://junglewise.ai/threats/cve-2026-11721-isc-bind-9-cache-poisoning-via-rrsig-label-count-discrepancy)