Bug 2494365

Summary: CVE-2026-27145 node-exporter: golang crypto/x509: Denial of Service via excessive processing of DNS SAN entries [fedora-all]
Product: [Fedora] Fedora Reporter: jkelly <jkelly>
Component: node-exporterAssignee: Mikel Olasagasti Uranga <mikel>
Status: ON_QA --- QA Contact:
Severity: high Docs Contact:
Priority: high    
Version: rawhideCC: go-sig, mikel
Target Milestone: ---Keywords: Security, SecurityTracking
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard: {"flaws": ["1765a0c8-adb1-4223-88bf-d35a230e256a"]}
Fixed In Version: Doc Type: ---
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On:    
Bug Blocks: 2484207    

Description jkelly 2026-06-29 14:27:45 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.

(*x509.Certificate).VerifyHostname previously called matchHostnames in a loop over all DNS Subject Alternative Name (SAN) entries. This caused strings.Split(host, ".") to execute repeatedly on the same input hostname. With a large DNS SAN list, verification costs scaled quadratically based on the number of SAN entries multiplied by the hostname's label count. Because x509.Verify validates hostnames before building the certificate chain, this overhead occurred even for untrusted certificates.

Comment 1 Fedora Update System 2026-07-11 12:20:18 UTC
FEDORA-2026-8a232fdbef (node-exporter-1.12.0-1.fc43) has been submitted as an update to Fedora 43.
https://bodhi.fedoraproject.org/updates/FEDORA-2026-8a232fdbef

Comment 2 Fedora Update System 2026-07-11 12:20:19 UTC
FEDORA-2026-c9a746635a (node-exporter-1.12.0-1.fc44) has been submitted as an update to Fedora 44.
https://bodhi.fedoraproject.org/updates/FEDORA-2026-c9a746635a

Comment 3 Fedora Update System 2026-07-12 01:33:09 UTC
FEDORA-2026-c9a746635a 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-c9a746635a`
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2026-c9a746635a

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

Comment 4 Fedora Update System 2026-07-12 01:51:20 UTC
FEDORA-2026-8a232fdbef 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-2026-8a232fdbef`
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2026-8a232fdbef

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

Comment 5 Fedora Update System 2026-07-16 01:58:49 UTC
FEDORA-2026-5924722657 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-2026-5924722657`
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2026-5924722657

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

Comment 6 Fedora Update System 2026-07-16 02:18:54 UTC
FEDORA-2026-81ed0bb2bb 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-2026-81ed0bb2bb`
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2026-81ed0bb2bb

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