01 Record

CVE-2026-1519

Excessive NSEC3 iterations cause high CPU load during insecure delegation validation

HighPUBLISHEDCNA: isc

CNA base score7.5 CVSS v3.xCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

View raw JSON

02 Description

Excessive NSEC3 iterations cause high CPU load during insecure delegation validation

03 Exploitation and scoring

Exploitation

Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.

SSVC decision

ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
AutomatableyesAn attacker can reliably automate reconnaissance through exploitation, so this scales.
Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

1.60% probability of exploitation activity in the next 30 days.

EPSS percentile

Ranks above 73.6% of scored records. A rank, not a probability.

NVD base score

7.5 (CVSS v3.x), scored by the NVD independently of the CNA.

NVD CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

NVD analysis status

Modified. NVD last modified this record on 2026-09-04.

Red Hat severity

Important. Red Hat's rating for its own products, not a CVSS rating.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

04 Metadata

Published

2026-03-25 13:25Z5 MO AGO

Last updated

2026-09-04 12:04Z10 HR AGO

Reserved

2026-01-28

Assigning CNA

isc

Record state

PUBLISHED

Severity

High (CVSS 7.5)

CNA CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Weaknesses

CWE-606Unchecked Input for Loop ConditionBase
CWE-770Allocation of Resources Without Limits or ThrottlingBase

Data version

5.2

Document digest

d9fc460489d774764c6d0e71a8d4a7f6cd5214ba9029b2489838dc38e7d82732

05 Affected products

VendorProductVersionsPlatforms

ISCBIND 99.11.0 to 9.16.50, 9.18.0 to 9.18.46, 9.20.0 to 9.20.20, 9.21.0 to 9.21.19, 9.11.3-S1 to 9.16.50-S1, 9.18.11-S1 to 9.18.46-S1, 9.20.9-S1 to 9.20.20-S1—

06 References

kb.isc.orgCVE-2026-1519https://kb.isc.org/docs/cve-2026-1519vendor-advisory
downloads.isc.orghttps://downloads.isc.org/isc/bind9/9.18.47patch
downloads.isc.orghttps://downloads.isc.org/isc/bind9/9.20.21patch
downloads.isc.orghttps://downloads.isc.org/isc/bind9/9.21.20patch
lists.debian.orghttps://lists.debian.org/debian-lts-announce/2026/04/msg00008.html
access.redhat.comhttps://access.redhat.com/security/cve/CVE-2026-1519vdb-entryx_refsource_REDHAT
bugzilla.redhat.comRHBZ#2451305https://bugzilla.redhat.com/show_bug.cgi?id=2451305issue-trackingx_refsource_REDHAT
security.access.redhat.comhttps://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-1519.jsonx_sadp-csaf-vex
access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:11372vendor-advisoryx_refsource_REDHAT
access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:11371vendor-advisoryx_refsource_REDHAT
access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:34048vendor-advisoryx_refsource_REDHAT
access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:40021vendor-advisoryx_refsource_REDHAT
access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:36610vendor-advisoryx_refsource_REDHAT
access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:43226vendor-advisoryx_refsource_REDHAT
access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:60019vendor-advisoryx_refsource_REDHAT
access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:29863vendor-advisoryx_refsource_REDHAT
access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:24851vendor-advisoryx_refsource_REDHAT
access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:8312vendor-advisoryx_refsource_REDHAT
access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:8352vendor-advisoryx_refsource_REDHAT
access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:8155vendor-advisoryx_refsource_REDHAT
access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:16064vendor-advisoryx_refsource_REDHAT
access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:16060vendor-advisoryx_refsource_REDHAT
access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:25171vendor-advisoryx_refsource_REDHAT
access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:15890vendor-advisoryx_refsource_REDHAT
access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:25083vendor-advisoryx_refsource_REDHAT
access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:29110vendor-advisoryx_refsource_REDHAT
access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:25214vendor-advisoryx_refsource_REDHAT
access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:24500vendor-advisoryx_refsource_REDHAT
access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:24934vendor-advisoryx_refsource_REDHAT
access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:8075vendor-advisoryx_refsource_REDHAT
access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:7915vendor-advisoryx_refsource_REDHAT
access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:6935vendor-advisoryx_refsource_REDHAT

07 Remediation

Upgrade to the patched release most closely related to your current version of BIND 9: 9.18.47, 9.20.21, 9.21.20, 9.18.47-S1, or 9.20.21-S1.

01 Record index

CVE-2026-1519

02 Description

03 Exploitation and scoring

04 Metadata

05 Affected products

06 References

07 Remediation

02 Records

CVE-2026-1519

02 Description

03 Exploitation and scoring

04 Metadata

05 Affected products

06 References

07 Remediation