Bug 2524349 - CVE-2026-18664 nsd: NSD: Access control bypass due to incorrect IP range comparison [epel-all]
Summary: CVE-2026-18664 nsd: NSD: Access control bypass due to incorrect IP range comp...
Keywords:
Status: CLOSED ERRATA
Alias: None
Product: Fedora EPEL
Classification: Fedora
Component: nsd
Version: epel10
Hardware: Unspecified
OS: Unspecified
high
high
Target Milestone: ---
Assignee: Paul Wouters
QA Contact: Fedora Extras Quality Assurance
URL:
Whiteboard: {"flaws": ["31a5971d-98e2-4dbc-a3a0-3...
Depends On:
Blocks: CVE-2026-18664
TreeView+ depends on / blocked
 
Reported: 2026-08-26 11:38 UTC by Vladimir Vasilev
Modified: 2026-09-11 18:51 UTC (History)
3 users (show)

Fixed In Version: nsd-4.15.1-1.el10_4 nsd-4.15.1-1.el10_3 nsd-4.15.1-1.el9 nsd-4.15.1-1.fc43 nsd-4.15.1-1.el10_2 nsd-4.15.1-1.fc44 nsd-4.15.1-1.fc45
Clone Of:
Environment:
Last Closed: 2026-09-08 00:26:50 UTC
Type: ---
Embargoed:


Attachments (Terms of Use)

Description Vladimir Vasilev 2026-08-26 11:38:59 UTC
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.

When ranges are used for access control (i.e. of the form 1.2.3.4-1.2.3.25), because NSD wrongly compares the IP address with the range on little endian systems, IPs that were meant to be allowed may be denied, and, IPs that were meant to be denied access could be allowed. An IPv4 address is compared with IPv4 ranges as unsigned 32 bit numbers directly with the endianness of the host, but the values to compare are in network byte order (big-endian).  With IPv6 addresses the comparison is done in 4 times a unsigned 32 bit number comparison, again with the endianness of the host where all values are actually in network bye order.

Comment 1 Fedora Update System 2026-08-28 07:30:45 UTC
FEDORA-2026-3ff003d397 (nsd-4.15.1-1.fc43) has been submitted as an update to Fedora 43.
https://bodhi.fedoraproject.org/updates/FEDORA-2026-3ff003d397

Comment 2 Fedora Update System 2026-08-28 07:30:46 UTC
FEDORA-EPEL-2026-5064a05224 (nsd-4.15.1-1.el9) has been submitted as an update to Fedora EPEL 9.
https://bodhi.fedoraproject.org/updates/FEDORA-EPEL-2026-5064a05224

Comment 3 Fedora Update System 2026-08-28 07:30:46 UTC
FEDORA-2026-c56ac69334 (nsd-4.15.1-1.fc45) has been submitted as an update to Fedora 45.
https://bodhi.fedoraproject.org/updates/FEDORA-2026-c56ac69334

Comment 4 Fedora Update System 2026-08-28 07:30:47 UTC
FEDORA-EPEL-2026-4a0c7835ec (nsd-4.15.1-1.el10_2) has been submitted as an update to Fedora EPEL 10.2.
https://bodhi.fedoraproject.org/updates/FEDORA-EPEL-2026-4a0c7835ec

Comment 5 Fedora Update System 2026-08-28 07:30:48 UTC
FEDORA-EPEL-2026-b69054a78f (nsd-4.15.1-1.el10_3) has been submitted as an update to Fedora EPEL 10.3.
https://bodhi.fedoraproject.org/updates/FEDORA-EPEL-2026-b69054a78f

Comment 6 Fedora Update System 2026-08-31 17:50:56 UTC
FEDORA-2026-bf1539678e has been pushed to the Fedora 44 testing repository.
Soon you'll be able to install the update with the following command:
`sudo dnf upgrade --enablerepo=updates-testing --refresh --advisory=FEDORA-2026-bf1539678e`
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2026-bf1539678e

See also https://fedoraproject.org/wiki/QA:Updates_Testing for more information on how to test updates.

Comment 7 Fedora Update System 2026-08-31 18:02:37 UTC
FEDORA-EPEL-2026-c16f6b76bf has been pushed to the Fedora EPEL 10.4 testing repository.

You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-EPEL-2026-c16f6b76bf

See also https://fedoraproject.org/wiki/QA:Updates_Testing for more information on how to test updates.

Comment 8 Fedora Update System 2026-08-31 18:11:38 UTC
FEDORA-2026-3ff003d397 has been pushed to the Fedora 43 testing repository.
Soon you'll be able to install the update with the following command:
`sudo dnf upgrade --enablerepo=updates-testing --refresh --advisory=FEDORA-2026-3ff003d397`
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2026-3ff003d397

See also https://fedoraproject.org/wiki/QA:Updates_Testing for more information on how to test updates.

Comment 9 Fedora Update System 2026-08-31 18:13:39 UTC
FEDORA-EPEL-2026-b69054a78f has been pushed to the Fedora EPEL 10.3 testing repository.

You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-EPEL-2026-b69054a78f

See also https://fedoraproject.org/wiki/QA:Updates_Testing for more information on how to test updates.

Comment 10 Fedora Update System 2026-08-31 18:22:46 UTC
FEDORA-EPEL-2026-5064a05224 has been pushed to the Fedora EPEL 9 testing repository.

You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-EPEL-2026-5064a05224

See also https://fedoraproject.org/wiki/QA:Updates_Testing for more information on how to test updates.

Comment 11 Fedora Update System 2026-08-31 18:25:58 UTC
FEDORA-2026-c56ac69334 has been pushed to the Fedora 45 testing repository.
Soon you'll be able to install the update with the following command:
`sudo dnf upgrade --enablerepo=updates-testing --refresh --advisory=FEDORA-2026-c56ac69334`
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2026-c56ac69334

See also https://fedoraproject.org/wiki/QA:Updates_Testing for more information on how to test updates.

Comment 12 Fedora Update System 2026-08-31 18:30:19 UTC
FEDORA-EPEL-2026-4a0c7835ec has been pushed to the Fedora EPEL 10.2 testing repository.

You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-EPEL-2026-4a0c7835ec

See also https://fedoraproject.org/wiki/QA:Updates_Testing for more information on how to test updates.

Comment 13 Fedora Update System 2026-09-08 00:26:50 UTC
FEDORA-EPEL-2026-c16f6b76bf (nsd-4.15.1-1.el10_4) has been pushed to the Fedora EPEL 10.4 stable repository.
If problem still persists, please make note of it in this bug report.

Comment 14 Fedora Update System 2026-09-08 00:30:08 UTC
FEDORA-EPEL-2026-b69054a78f (nsd-4.15.1-1.el10_3) has been pushed to the Fedora EPEL 10.3 stable repository.
If problem still persists, please make note of it in this bug report.

Comment 15 Fedora Update System 2026-09-08 00:44:41 UTC
FEDORA-EPEL-2026-5064a05224 (nsd-4.15.1-1.el9) has been pushed to the Fedora EPEL 9 stable repository.
If problem still persists, please make note of it in this bug report.

Comment 16 Fedora Update System 2026-09-08 00:55:55 UTC
FEDORA-2026-3ff003d397 (nsd-4.15.1-1.fc43) has been pushed to the Fedora 43 stable repository.
If problem still persists, please make note of it in this bug report.

Comment 17 Fedora Update System 2026-09-08 01:04:26 UTC
FEDORA-EPEL-2026-4a0c7835ec (nsd-4.15.1-1.el10_2) has been pushed to the Fedora EPEL 10.2 stable repository.
If problem still persists, please make note of it in this bug report.

Comment 18 Fedora Update System 2026-09-08 01:10:46 UTC
FEDORA-2026-bf1539678e (nsd-4.15.1-1.fc44) has been pushed to the Fedora 44 stable repository.
If problem still persists, please make note of it in this bug report.

Comment 19 Fedora Update System 2026-09-11 18:51:22 UTC
FEDORA-2026-c56ac69334 (nsd-4.15.1-1.fc45) has been pushed to the Fedora 45 stable repository.
If problem still persists, please make note of it in this bug report.


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