Answer in brief
CVE-2026-123596 records a High severity (CVSS 8.7) vulnerability in Hickory DNS through 0.26.0-alpha.1 DNSSEC Validation Bypass via Ancestor-Delegation NSEC. The current sources do not mark it as known exploited. The current feed maps hickory-dns/hickory-dns (generic), hickory-dns/hickory-dns (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 8.7. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps hickory-dns/hickory-dns (generic), hickory-dns/hickory-dns (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| hickory-dns/hickory-dnsgeneric | >=0 <=0.26.0-alpha.1 | Not reported |
| hickory-dns/hickory-dnsgeneric | >=0.26.0-beta.1 <0.26.2 | 0.26.2 |
Published upstream
Nov 8, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Nov 8, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Nov 8, 2026
Hickory DNS hickory-proto through 0.26.0-alpha.1 and hickory-net 0.26.0-beta.1 before 0.26.2 contain a DNSSEC validation flaw in the validating recursor's NSEC handler that accepts parent-side ancestor-delegation NSEC records as proof of nonexistence for names below the zone cut. An on-path attacker, rogue parent nameserver, or attacker winning a port and TXID race can deliver one forged NXDOMAIN response built from genuinely signed parent NSEC records, causing authenticated denial of existing child-zone names cached for the negative TTL.
Quoted source text, attributed separately from HOL analysis.