Memory exhaustion in Hickory DNS DoH server via incomplete request bodies
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Fixed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-770.
Summary
Hickory DNS before 0.26.2 contains a resource exhaustion flaw in its DNS-over-HTTPS HTTP/2 server. The server lacks sufficient timeouts or limits for incomplete request bodies, which is CWE-770. A remote unauthenticated attacker can open DoH connections, send incomplete request bodies, and hold them open to exhaust server memory.
Written with Claude Haiku 5.5 from the sources below · 2026-11-08
Description from the CNA
Hickory DNS before 0.26.2 contains a resource exhaustion vulnerability in its DNS-over-HTTPS HTTP/2 server that lacks sufficient timeouts or limits for incomplete request bodies. Remote attackers can open DoH connections, send incomplete request bodies, and hold connections open to exhaust server memory.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| hickory-dns | hickory-dns | before 0.26.2 | 0.26.2 | Patch available | CNA |
- hickory-dns Vendorhickory-dns Affected before 0.26.2 Fixed in 0.26.2 Patch available CNA
Remediation
Upgrade hickory-dns to version 0.26.2 or later.
Written with Claude Haiku 5.5 from the sources below · 2026-11-08
- Fix · CNA hickory-dns (hickory-dns) Fixed in 0.26.2
Fixed in the same release
Records fixed by the same vendor advisory or release, as the CNA lists them.
- Release ·
hickory-dns 0.26.2
36 records Highest priority Priority MEDIUM 36 MEDIUM
Other records, highest priority first
- TI-2026-86729 DNSSEC nonexistence forgery in Hickory DNS via wraparound NSECPriority MEDIUM 54
- TI-2026-86748 Resource exhaustion in hickory-dns recursor via glueless NS referralsPriority MEDIUM 53
- TI-2026-86747 DNSSEC validation bypass in Hickory DNS via RRSIG signer namePriority MEDIUM 53
Timeline
- 2026-11-08 Threatist record created from CVE-2026-123575
- 2026-11-08 Alias added: GHSA-p3hw-2hh6-3p6w
References
More hickory-dns vulnerabilities
- TI-2025-18857 DNSSEC validation may accept broken authentication chains CVSS 4.0MEDIUM 5.7
- TI-2026-86729 DNSSEC nonexistence forgery in Hickory DNS via wraparound NSEC CVSS 4.0HIGH 8.9
- TI-2026-86750 CPU exhaustion in Hickory DNS hickory-proto via BinEncoder name compression CVSS 4.0HIGH 8.7
- TI-2026-86749 Hickory DNS NSEC3 validation loop enables denial of service CVSS 4.0HIGH 8.7
- TI-2026-86748 Resource exhaustion in hickory-dns recursor via glueless NS referrals CVSS 4.0HIGH 8.7
- TI-2026-86747 DNSSEC validation bypass in Hickory DNS via RRSIG signer name CVSS 4.0HIGH 8.7
Sources
- CVE-2026-123575 · CVE Program
- CVE-2026-123575 · NVD
- GHSA-p3hw-2hh6-3p6w · GitHub Advisory Database · CC BY 4.0
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