CVE-2026-19667: ISC BIND 9 · Numeric Truncation Error
Affects ISC BIND 9Source CVE Database V5
Not known to be exploited · CVSS 7.5 High.
Data as of 30 Oct 2026, 20:25 UTC
- EPSS
- 0.5% chance of exploitation in 30 days – higher than 47% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 16 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| ISCBIND 9 | Affected
| Fixed in– |
GitHubisc/bind9pkg:github/isc/bind9Other threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Until a fix is confirmed, consider restricting or monitoring DNS responses from authoritative servers to mitigate potential exploitation.
Description
CVE-2026-19667 is a numeric truncation error vulnerability in ISC BIND 9's named DNS service. An attacker-controlled authoritative DNS server can send a crafted negative response of exactly 65536 bytes, causing named to create a zero-byte negative cache entry. Subsequent accesses to this cache entry cause the named service to abort, resulting in a denial of service. This affects multiple BIND 9 versions including 9.11.0 through 9.18.50, 9.20.0 through 9.20.27, 9.21.0 through 9.21.25, and their S1 variants.