Answer in brief
CVE-2026-81563 records a High severity (CVSS 7.5) vulnerability in SVCB AliasMode additional-data error leaks qpcache references. The current sources do not mark it as known exploited. The current feed maps ISC/BIND 9 (generic), ISC/BIND 9 (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 7.5. 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 ISC/BIND 9 (generic), ISC/BIND 9 (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| ISC/BIND 9generic | 9.18.0 || 9.20.0 || 9.21.0 || 9.18.11-S1 || 9.20.9-S1 | Not reported |
| ISC/BIND 9generic | >=9.18.0 <=9.18.50 || >=9.20.0 <=9.20.27 || >=9.21.0 <=9.21.25 || >=9.18.11-S1 <=9.18.50-S1 || >=9.20.9-S1 <=9.20.27-S1 | Not reported |
Published upstream
Sep 16, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 26, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Sep 16, 2026
A BIND resolver encountering an SVCB/HTTPS AliasMode record referencing 14 or more SVCB/HTTPS ServiceMode records may fail to properly deallocate internal resources. If this happens repeatedly, resource exhaustion will eventually prevent the resolver from performing new recursive lookups. This issue affects BIND 9 versions 9.18.0 through 9.18.50, 9.20.0 through 9.20.27, 9.21.0 through 9.21.25, 9.18.11-S1 through 9.18.50-S1, and 9.20.9-S1 through 9.20.27-S1.
Quoted source text, attributed separately from HOL analysis.