Bug 2494188 - CVE-2026-12244 nsd: A specially crafted SVCB RR can cause a heap overflow of up to 65509 attacker controlled bytes. [fedora-all]
Summary: CVE-2026-12244 nsd: A specially crafted SVCB RR can cause a heap overflow of ...
Keywords:
Status: CLOSED ERRATA
Alias: None
Product: Fedora
Classification: Fedora
Component: nsd
Version: rawhide
Hardware: Unspecified
OS: Unspecified
high
high
Target Milestone: ---
Assignee: Paul Wouters
QA Contact: Fedora Extras Quality Assurance
URL:
Whiteboard: {"flaws": ["beefe42f-ed4c-4824-860a-0...
Depends On:
Blocks: CVE-2026-12244
TreeView+ depends on / blocked
 
Reported: 2026-06-29 13:49 UTC by Marco Benatto
Modified: 2026-08-03 01:05 UTC (History)
3 users (show)

Fixed In Version: nsd-4.15.0-1.el10_3 nsd-4.15.0-1.el10_2 nsd-4.15.0-1.fc44 nsd-4.15.0-1.fc43
Clone Of:
Environment:
Last Closed: 2026-08-03 00:25:41 UTC
Type: ---
Embargoed:


Attachments (Terms of Use)

Description Marco Benatto 2026-06-29 13:49:04 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.

If NSD is configured as secondary for a zone, the primary of that zone can crash NSD with an AXFR containing a DNS message with a special crafted SVCB RR with an rdata size of 65512, that let's an (uint16_t) variable that is used to allocate space needed for the RR wrap (because total size > 65535), causing a heap overflow. The attacker can perform a controlled (RCE class) head write of up to 65509 bytes.

Even though the data is from a configured primary inside NSD's trust boundary, we do consider the risk significant enough for multi-tenant secondary DNS deployments, given the potential severity of the attack.

Comment 1 Fedora Update System 2026-07-25 09:35:04 UTC
FEDORA-EPEL-2026-484870f7f9 (nsd-4.15.0-1.el10_3) has been submitted as an update to Fedora EPEL 10.3.
https://bodhi.fedoraproject.org/updates/FEDORA-EPEL-2026-484870f7f9

Comment 2 Fedora Update System 2026-07-25 09:35:23 UTC
FEDORA-2026-0b77a23312 (nsd-4.15.0-1.fc43) has been submitted as an update to Fedora 43.
https://bodhi.fedoraproject.org/updates/FEDORA-2026-0b77a23312

Comment 3 Fedora Update System 2026-07-26 01:25:45 UTC
FEDORA-EPEL-2026-484870f7f9 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-2026-484870f7f9

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

Comment 4 Fedora Update System 2026-07-26 01:35:11 UTC
FEDORA-EPEL-2026-6030526353 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-2026-6030526353

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

Comment 5 Fedora Update System 2026-07-26 01:35:17 UTC
FEDORA-2026-0b77a23312 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-2026-0b77a23312`
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2026-0b77a23312

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

Comment 6 Fedora Update System 2026-07-26 01:56:18 UTC
FEDORA-2026-d86ace09cb 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-d86ace09cb`
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2026-d86ace09cb

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

Comment 7 Fedora Update System 2026-08-03 00:25:41 UTC
FEDORA-EPEL-2026-484870f7f9 (nsd-4.15.0-1.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 8 Fedora Update System 2026-08-03 00:36:07 UTC
FEDORA-EPEL-2026-6030526353 (nsd-4.15.0-1.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 9 Fedora Update System 2026-08-03 00:45:02 UTC
FEDORA-2026-d86ace09cb (nsd-4.15.0-1.fc44) has been pushed to the Fedora 44 stable repository.
If problem still persists, please make note of it in this bug report.

Comment 10 Fedora Update System 2026-08-03 01:05:15 UTC
FEDORA-2026-0b77a23312 (nsd-4.15.0-1.fc43) has been pushed to the Fedora 43 stable repository.
If problem still persists, please make note of it in this bug report.


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