# CVE-2026-1519: Excessive NSEC3 iterations cause high CPU load during insecure delegation validation > A maliciously crafted zone causes excessive CPU consumption in BIND resolvers during DNSSEC validation, leading to denial of service. - **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`) - **Exploited in the wild:** Not known - **Login needed:** Not needed - **Attackable:** Over the internet - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 25 Mar 2026 - **Updated:** 17 Sep 2026 - **Also known as:** ALPINE-CVE-2026-1519, ALSA-2026:7915, ALSA-2026:8075, ALSA-2026:8155, ALSA-2026:8312, ALSA-2026:8352, AZL-80978, BELL-CVE-2026-1519, CLSA-2026-1775735258, CLSA-2026-1777452704, CLSA-2026-1777453021, CLSA-2026-1777541752, CLSA-2026-1779214855, CLSA-2026-1779748226, CLSA-2026-1779960293, CLSA-2026-1780065945, CLSA-2026-1780066979, CLSA-2026-1780067897, CLSA-2026-1785886464, CLSA-2026-1786881091, CLSA-2026-1787093019, DEBIAN-CVE-2026-1519, DSA-6181-1, GHSA-84m6-p53c-x4wp, MINI-f6vv-2q2m-q2f9, OESA-2026-2058, OESA-2026-2059, OESA-2026-2060, OESA-2026-2061, OESA-2026-2062, RHSA-2026:11371, RHSA-2026:11372, RHSA-2026:15890, RHSA-2026:16060, RHSA-2026:16064, RHSA-2026:24500, RHSA-2026:24851, RHSA-2026:24934, RHSA-2026:25083, RHSA-2026:25171, RHSA-2026:25214, RHSA-2026:29110, RHSA-2026:7915, RHSA-2026:8075, RHSA-2026:8155, RHSA-2026:8312, RHSA-2026:8352, RLSA-2026:7915, RLSA-2026:8075, RLSA-2026:8155, RLSA-2026:8312, RLSA-2026:8352, SUSE-SU-2026:1209-1, SUSE-SU-2026:1229-1, SUSE-SU-2026:1230-1, SUSE-SU-2026:1312-1, SUSE-SU-2026:1366-1, SUSE-SU-2026:1428-1, UBUNTU-CVE-2026-1519 ## What is CVE-2026-1519? CVE-2026-1519 is a high-severity denial of service vulnerability in Isc Bind, published on 25 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim. ### Official 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. Weakness: CWE-770 (Allocation of Resources Without Limits or Throttling), CWE-606 (Unchecked Input for Loop Condition) ## Which versions are affected by CVE-2026-1519? It affects 1 product. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `bind-doc` | AlmaLinux:10 | All versions | 32:9.18.33-10.el10_1.3 | | `bind-license` | AlmaLinux:10 | All versions | 32:9.18.33-10.el10_1.3 | | `bind` | AlmaLinux:8 | All versions | 32:9.11.36-16.el8_10.7 | | `bind-chroot` | AlmaLinux:8 | All versions | 32:9.11.36-16.el8_10.7 | | `bind-devel` | AlmaLinux:8 | All versions | 32:9.11.36-16.el8_10.7 | | `bind-export-devel` | AlmaLinux:8 | All versions | 32:9.11.36-16.el8_10.7 | | `bind-export-libs` | AlmaLinux:8 | All versions | 32:9.11.36-16.el8_10.7 | | `bind-libs` | AlmaLinux:8 | All versions | 32:9.11.36-16.el8_10.7 | | `bind-libs-lite` | AlmaLinux:8 | All versions | 32:9.11.36-16.el8_10.7 | | `bind-license` | AlmaLinux:8 | All versions | 32:9.11.36-16.el8_10.7 | | `bind-lite-devel` | AlmaLinux:8 | All versions | 32:9.11.36-16.el8_10.7 | | `bind-pkcs11` | AlmaLinux:8 | All versions | 32:9.11.36-16.el8_10.7 | | `bind-pkcs11-devel` | AlmaLinux:8 | All versions | 32:9.11.36-16.el8_10.7 | | `bind-pkcs11-libs` | AlmaLinux:8 | All versions | 32:9.11.36-16.el8_10.7 | | `bind-pkcs11-utils` | AlmaLinux:8 | All versions | 32:9.11.36-16.el8_10.7 | | `bind-sdb` | AlmaLinux:8 | All versions | 32:9.11.36-16.el8_10.7 | | `bind-sdb-chroot` | AlmaLinux:8 | All versions | 32:9.11.36-16.el8_10.7 | | `bind-utils` | AlmaLinux:8 | All versions | 32:9.11.36-16.el8_10.7 | | `bind9.16` | AlmaLinux:8 | All versions | 32:9.16.23-0.22.el8_10.5 | | `bind9.16-chroot` | AlmaLinux:8 | All versions | 32:9.16.23-0.22.el8_10.5 | | `bind9.16-devel` | AlmaLinux:8 | All versions | 32:9.16.23-0.22.el8_10.5 | | `bind9.16-dnssec-utils` | AlmaLinux:8 | All versions | 32:9.16.23-0.22.el8_10.5 | | `bind9.16-doc` | AlmaLinux:8 | All versions | 32:9.16.23-0.22.el8_10.5 | | `bind9.16-libs` | AlmaLinux:8 | All versions | 32:9.16.23-0.22.el8_10.5 | | `bind9.16-license` | AlmaLinux:8 | All versions | 32:9.16.23-0.22.el8_10.5 | | `bind9.16-utils` | AlmaLinux:8 | All versions | 32:9.16.23-0.22.el8_10.5 | | `python3-bind` | AlmaLinux:8 | All versions | 32:9.11.36-16.el8_10.7 | | `python3-bind9.16` | AlmaLinux:8 | All versions | 32:9.16.23-0.22.el8_10.5 | | `bind` | AlmaLinux:9 | All versions | 32:9.16.23-34.el9_7.2 | | `bind-chroot` | AlmaLinux:9 | All versions | 32:9.16.23-34.el9_7.2 | | `bind-devel` | AlmaLinux:9 | All versions | 32:9.16.23-34.el9_7.2 | | `bind-dnssec-doc` | AlmaLinux:9 | All versions | 32:9.16.23-34.el9_7.2 | | `bind-dnssec-utils` | AlmaLinux:9 | All versions | 32:9.16.23-34.el9_7.2 | | `bind-doc` | AlmaLinux:9 | All versions | 32:9.16.23-34.el9_7.2 | | `bind-libs` | AlmaLinux:9 | All versions | 32:9.16.23-34.el9_7.2 | | `bind-license` | AlmaLinux:9 | All versions | 32:9.16.23-34.el9_7.2 | | `bind-utils` | AlmaLinux:9 | All versions | 32:9.16.23-34.el9_7.2 | | `bind9.18` | AlmaLinux:9 | All versions | 32:9.18.29-5.el9_7.4 | | `bind9.18-chroot` | AlmaLinux:9 | All versions | 32:9.18.29-5.el9_7.4 | | `bind9.18-devel` | AlmaLinux:9 | All versions | 32:9.18.29-5.el9_7.4 | Products: Isc Bind. ## How do I fix CVE-2026-1519? Apply the vendor's patch. ## Is CVE-2026-1519 being exploited? There is no known exploitation of CVE-2026-1519 in the wild and no public exploit code. ## Other vulnerabilities in Isc Bind - [CVE-2008-0122](https://insights.sbomify.com/CVE-2008-0122/): Memory corruption in n/a (critical 10.0) - [CVE-2001-0010](https://insights.sbomify.com/CVE-2001-0010/): Memory corruption in n/a (critical 10.0) - [CVE-2001-0011](https://insights.sbomify.com/CVE-2001-0011/): Memory corruption in n/a (critical 10.0) - [CVE-2001-0013](https://insights.sbomify.com/CVE-2001-0013/): Memory corruption in n/a (critical 10.0) - [CVE-2000-1029](https://insights.sbomify.com/CVE-2000-1029/): Memory corruption in n/a (critical 10.0) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2026-1519 and fix it if it is affected. What it is: CVE-2026-1519 is a high-severity denial of service vulnerability in Isc Bind, published on 25 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim. Exploitation: There is no known exploitation of CVE-2026-1519 in the wild and no public exploit code. Affected product: Isc Bind. No package-level version data is available, so check the vendor advisory linked from the reference page. Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2026-1519/ (Markdown: https://insights.sbomify.com/CVE-2026-1519/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2026-1519 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-1519 - OSV: https://osv.dev/vulnerability/CVE-2026-1519 --- From sbomify Insights: https://insights.sbomify.com/CVE-2026-1519/ Summaries are generated and may contain mistakes; the official description above is the record.