Bug 2542264 (CVE-2026-100890)

Summary:	CVE-2026-100890 opendmarc: OpenDMARC: Denial of service via null pointer dereference in SPF parser
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security DevOps Team <prodsec-dev>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	Keywords:	Security
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Hardware:	All
OS:	Linux
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Doc Text:	A flaw was found in OpenDMARC. A remote attacker could cause a denial of service (DoS) by supplying specially crafted Sender Policy Framework (SPF) records. Due to improper input validation when parsing IPv6 addresses in the opendmarc_spf_ipv6_explode function, the application triggers a null pointer dereference, resulting in a service crash.	Story Points:	---
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oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	2542276, 2542277
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Description OSIDB Bzimport 2026-09-28 00:51:18 UTC

A flaw has been found in Trusted Domain Project OpenDMARC up to 1.4.2. Affected by this vulnerability is the function opendmarc_spf_ipv6_explode in the library libopendmarc/opendmarc_spf.c of the component SPF Parser. This manipulation of the argument cp causes null pointer dereference. It is possible to initiate the attack remotely. The exploit has been published and may be used. The vendor was contacted early about this disclosure but did not respond in any way.