CVE-2026-1519

7.5

HIGH CVSS 3.1

Excessive NSEC3 iterations cause high CPU load during insecure delegation validation

Overview

Description

If a BIND resolver is performing DNSSEC validation and encounters a maliciously crafted zone, the resolver may consume excessive CPU. Authoritative-only servers are generally unaffected, although there are circumstances where authoritative servers may make recursive queries (see: https://kb.isc.org/docs/why-does-my-authoritative-server-make-recursive-queries). This issue affects BIND 9 versions 9.11.0 through 9.16.50, 9.18.0 through 9.18.46, 9.20.0 through 9.20.20, 9.21.0 through 9.21.19, 9.11.3-S1 through 9.16.50-S1, 9.18.11-S1 through 9.18.46-S1, and 9.20.9-S1 through 9.20.20-S1.

Details

INFO

Published Date :

March 25, 2026, 2:16 p.m.

Last Modified :

April 13, 2026, 10:16 a.m.

Remotely Exploit :

Yes !

Source :

[email protected]

Impact

Affected Products

The following products are affected by CVE-2026-1519 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID	Vendor	Product	Action
1	Isc	bind

: Total Affected Vendor : 1 | Products : 1

Scoring

CVSS Scores

The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.

Score	Version	Severity	Vector	Exploitability Score	Impact Score	Source
	CVSS 3.1	HIGH				[email protected]
	CVSS 3.1	HIGH				MITRE-CVE

Solution

Update BIND resolvers to a patched version to prevent excessive CPU consumption.

Update BIND to a non-vulnerable version.
Disable DNSSEC validation if unable to update.
Avoid recursive queries on authoritative servers.

Public PoC/Exploit Available at Github

CVE-2026-1519 has a 2 public PoC/Exploit available at Github. Go to the Public Exploits tab to see the list.

References

References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-1519.

URL	Resource
https://downloads.isc.org/isc/bind9/9.18.47
https://downloads.isc.org/isc/bind9/9.20.21
https://downloads.isc.org/isc/bind9/9.21.20
https://kb.isc.org/docs/cve-2026-1519
https://lists.debian.org/debian-lts-announce/2026/04/msg00008.html

CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-1519 is associated with the following CWEs:

CWE-606: Unchecked Input for Loop Condition

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-1519 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

w4zu/Debian_security

DSA and DLA for Debian last 14 days

Python

Updated: 1 week, 2 days ago

0 stars 0 fork 0 watcher

Born at : Feb. 12, 2025, 2:08 p.m. This repo has been linked 126 different CVEs too.

runwhen-contrib/helm-charts

All Public RunWhen Helm Charts - Managed by terraform

Shell Dockerfile Go Template

Updated: 1 week, 3 days ago

1 stars 0 fork 0 watcher

Born at : Sept. 18, 2023, 10:09 a.m. This repo has been linked 98 different CVEs too.

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-1519 vulnerability anywhere in the article.

Daily CyberSecurity

BIND 9 Security Alert: ISC Releases Patches for Trio of Vulnerabilities

The Internet Systems Consortium (ISC) has issued an important security advisory for BIND 9, the world’s most widely used DNS software. The update addresses three distinct vulnerabilities that could al ...

Published Date: Mar 26, 2026 (2 weeks, 5 days ago)

Results are limited to the first 20 news articles due to potential performance issues.

The following table lists the changes that have been made to the CVE-2026-1519 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

CVE Modified by af854a3a-2127-422b-91ae-364da2661108

Apr. 13, 2026

Action	Type	Old Value	New Value
Added	Reference		https://lists.debian.org/debian-lts-announce/2026/04/msg00008.html

New CVE Received by [email protected]

Mar. 25, 2026

Action	Type	New Value
Added	Description	If a BIND resolver is performing DNSSEC validation and encounters a maliciously crafted zone, the resolver may consume excessive CPU. Authoritative-only servers are generally unaffected, although there are circumstances where authoritative servers may make recursive queries (see: https://kb.isc.org/docs/why-does-my-authoritative-server-make-recursive-queries). This issue affects BIND 9 versions 9.11.0 through 9.16.50, 9.18.0 through 9.18.46, 9.20.0 through 9.20.20, 9.21.0 through 9.21.19, 9.11.3-S1 through 9.16.50-S1, 9.18.11-S1 through 9.18.46-S1, and 9.20.9-S1 through 9.20.20-S1.
Added	CVSS V3.1	AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Added	CWE	CWE-606
Added	Reference	https://downloads.isc.org/isc/bind9/9.18.47
Added	Reference	https://downloads.isc.org/isc/bind9/9.20.21
Added	Reference	https://downloads.isc.org/isc/bind9/9.21.20
Added	Reference	https://kb.isc.org/docs/cve-2026-1519

EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.