# CVE-2025-13878: ISC BIND 9 denial of service via malformed BRID or HHIT records

Source: https://junglewise.ai/threats/cve-2025-13878-isc-bind-9-denial-of-service-via-malformed-brid-or-hhit-records  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-01-21. Updated: 2026-06-30  
License: CC BY 4.0 with a link back

CVE-2025-13878 · Severity: high · CVSS 7.5 · Published 2026-01-21

A vulnerability in BIND 9, a widely used system for translating domain names into IP addresses, allows a remote attacker to crash the service. By sending a specially crafted DNS request containing malformed records, an attacker can cause the 'named' process to terminate unexpectedly. This results in a denial-of-service (DoS) condition, preventing users and systems from resolving website addresses and other network services. Both authoritative DNS servers and recursive resolvers are affected.

Technologies: [Isc BIND 9](https://junglewise.ai/threats/technologies/bind-9), [Isc BIND 9 Supported Preview Edition](https://junglewise.ai/threats/technologies/bind-9-supported-preview-edition). Vendors: [Isc](https://junglewise.ai/threats/vendors/isc).

## Quick answers

**Is CVE-2025-13878 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2025-13878 being exploited in the wild.

**How severe is CVE-2025-13878?** High severity, with a CVSS score of 7.5, published 21 January 2026.

**Which products and versions are affected?** Isc BIND 9 9.18.40 through 9.18.43, 9.20.13 through 9.20.17, 9.21.12 through 9.21.16; Isc BIND 9 Supported Preview Edition 9.18.40-S1 through 9.18.43-S1, 9.20.13-S1 through 9.20.17-S1.

**Is there a fix for CVE-2025-13878?** A patch was published on 2026-01-21: Patched versions 9.18.44, 9.20.18, and 9.21.17 released Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2025-13878 attacked?** It is attacked over the network, in a hosted service.

**Am I affected by CVE-2025-13878?** Check whether you run Isc BIND 9 or Isc BIND 9 Supported Preview Edition 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 reachable assertion vulnerability (CWE-617) exists in BIND 9 due to improper validation of malformed BRID and HHIT resource records. An unauthenticated remote attacker can trigger this vulnerability by sending a DNS query that results in the processing of a corrupt or malicious record. This causes the 'named' process to crash, affecting both authoritative servers and resolvers. The issue is fixed in BIND versions 9.18.44, 9.20.18, and 9.21.17. No workarounds are currently known.

## Affected products

- ISC BIND 9 9.18.40 through 9.18.43, 9.20.13 through 9.20.17, 9.21.12 through 9.21.16
- ISC BIND 9 Supported Preview Edition 9.18.40-S1 through 9.18.43-S1, 9.20.13-S1 through 9.20.17-S1

## Timeline

- 2026-01-14: other: Early notification provided by ISC
- 2026-01-21: advisory: Public disclosure by ISC
- 2026-01-21: patched: Patched versions 9.18.44, 9.20.18, and 9.21.17 released

## References

- [https://downloads.isc.org/isc/bind9/9.18.44](https://downloads.isc.org/isc/bind9/9.18.44)
- [https://downloads.isc.org/isc/bind9/9.20.18](https://downloads.isc.org/isc/bind9/9.20.18)
- [https://downloads.isc.org/isc/bind9/9.21.17](https://downloads.isc.org/isc/bind9/9.21.17)
- [https://kb.isc.org/docs/cve-2025-13878](https://kb.isc.org/docs/cve-2025-13878)
- [http://www.openwall.com/lists/oss-security/2026/01/21/3](http://www.openwall.com/lists/oss-security/2026/01/21/3)
- [https://access.redhat.com/errata/RHSA-2026:6935](https://access.redhat.com/errata/RHSA-2026:6935)
- [https://access.redhat.com/security/cve/CVE-2025-13878](https://access.redhat.com/security/cve/CVE-2025-13878)

## 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)