MNBSD-2026-55: unbounded name compression causes degradation of service

Description

In certain cases unbound performs unbounded DNS name compression, which can cause a degradation of service (Denial of Service). Reported by Qifan Zhang, Palo Alto Networks. Fixed in unbound 1.25.1.

Affected Versions

unbound

Recommendations

No specific recommendations provided.

References

• https://nvd.nist.gov/vuln/detail/CVE-2026-44390
• https://nlnetlabs.nl/projects/unbound/security-advisories/

Additional Information

Aliases: CVE-2026-44390

Published: June 11, 2026
Last Modified: June 11, 2026