CVE-2026-35091

Corosync: corosync: denial of service and information disclosure via crafted udp packet

Published Apr 1, 2026 CVSS 3.1 · 8.2 High EPSS < 1% KEV · Not listed
Description
A flaw was found in Corosync. A remote unauthenticated attacker can exploit a wrong return value vulnerability in the Corosync membership commit token sanity check by sending a specially crafted User Datagram Protocol (UDP) packet. This can lead to an out-of-bounds read, causing a denial of service (DoS) and potentially disclosing limited memory contents

Remediation

Vendor Workaround

Systems using totemudp or totemudpu should migrate to the supported knet transport and enable encryption. Disabling the Corosync service is a valid workaround if clustering is not required, but for active clusters, enabling encryption via knet is the preferred and recommended approach.

Tracking

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Advisories

Source ID Title
Debian DLA Debian DLA DLA-4608-1 corosync security update
Debian DSA Debian DSA DSA-6261-1 corosync security update
Ubuntu USN Ubuntu USN USN-8170-1 Corosync vulnerabilities
History
Type Values Removed Values Added
CPEs cpe:/o:redhat:enterprise_linux:7 cpe:/o:redhat:enterprise_linux:7::server
References
Type Values Removed Values Added
CPEs cpe:/o:redhat:enterprise_linux:10.2
References
Type Values Removed Values Added
Description A flaw was found in Corosync. A remote unauthenticated attacker can exploit a wrong return value vulnerability in the Corosync membership commit token sanity check by sending a specially crafted User Datagram Protocol (UDP) packet. This can lead to an out-of-bounds read, causing a denial of service (DoS) and potentially disclosing limited memory contents. This vulnerability affects Corosync when running in totemudp/totemudpu mode, which is the default configuration. A flaw was found in Corosync. A remote unauthenticated attacker can exploit a wrong return value vulnerability in the Corosync membership commit token sanity check by sending a specially crafted User Datagram Protocol (UDP) packet. This can lead to an out-of-bounds read, causing a denial of service (DoS) and potentially disclosing limited memory contents
Type Values Removed Values Added
CPEs cpe:/a:redhat:rhel_e4s:9.0::appstream
cpe:/a:redhat:rhel_e4s:9.0::highavailability
cpe:/a:redhat:rhel_e4s:9.0::resilientstorage
cpe:/a:redhat:rhel_e4s:9.2::appstream
cpe:/a:redhat:rhel_e4s:9.2::highavailability
cpe:/a:redhat:rhel_e4s:9.2::resilientstorage
References
Type Values Removed Values Added
First Time appeared Redhat rhel Eus
CPEs cpe:/a:redhat:rhel_eus:9.4::appstream
cpe:/a:redhat:rhel_eus:9.4::crb
cpe:/a:redhat:rhel_eus:9.4::highavailability
cpe:/a:redhat:rhel_eus:9.4::resilientstorage
cpe:/a:redhat:rhel_eus:9.6::appstream
cpe:/a:redhat:rhel_eus:9.6::crb
cpe:/a:redhat:rhel_eus:9.6::highavailability
cpe:/a:redhat:rhel_eus:9.6::resilientstorage
Vendors & Products Redhat rhel Eus
References
Type Values Removed Values Added
First Time appeared Redhat rhel Aus
Redhat rhel E4s
Redhat rhel Eus Long Life
Redhat rhel Tus
CPEs cpe:/a:redhat:rhel_aus:8.4::appstream
cpe:/a:redhat:rhel_aus:8.4::highavailability
cpe:/a:redhat:rhel_aus:8.6::appstream
cpe:/a:redhat:rhel_e4s:8.6::appstream
cpe:/a:redhat:rhel_e4s:8.6::highavailability
cpe:/a:redhat:rhel_e4s:8.8::appstream
cpe:/a:redhat:rhel_e4s:8.8::highavailability
cpe:/a:redhat:rhel_eus_long_life:8.4::appstream
cpe:/a:redhat:rhel_eus_long_life:8.4::highavailability
cpe:/a:redhat:rhel_tus:8.6::appstream
cpe:/a:redhat:rhel_tus:8.6::highavailability
cpe:/a:redhat:rhel_tus:8.8::appstream
cpe:/a:redhat:rhel_tus:8.8::highavailability
Vendors & Products Redhat rhel Aus
Redhat rhel E4s
Redhat rhel Eus Long Life
Redhat rhel Tus
References
Type Values Removed Values Added
First Time appeared Redhat enterprise Linux Eus
CPEs cpe:/o:redhat:enterprise_linux_eus:10.0
Vendors & Products Redhat enterprise Linux Eus
References
Type Values Removed Values Added
CPEs cpe:/o:redhat:enterprise_linux:9 cpe:/a:redhat:enterprise_linux:9::appstream
cpe:/a:redhat:enterprise_linux:9::crb
cpe:/a:redhat:enterprise_linux:9::highavailability
cpe:/a:redhat:enterprise_linux:9::resilientstorage
References
Type Values Removed Values Added
CPEs cpe:/o:redhat:enterprise_linux:8 cpe:/a:redhat:enterprise_linux:8::appstream
cpe:/a:redhat:enterprise_linux:8::crb
cpe:/a:redhat:enterprise_linux:8::highavailability
cpe:/a:redhat:enterprise_linux:8::resilientstorage
References
Type Values Removed Values Added
CPEs cpe:/o:redhat:enterprise_linux:10 cpe:/o:redhat:enterprise_linux:10.1
References
Type Values Removed Values Added
CPEs cpe:2.3:a:corosync:corosync:-:*:*:*:*:*:*:*
cpe:2.3:a:redhat:openshift:4.0:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux:10.0:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux:9.0:*:*:*:*:*:*:*
Type Values Removed Values Added
First Time appeared Corosync
Corosync corosync
Redhat openshift Container Platform
Vendors & Products Corosync
Corosync corosync
Redhat openshift Container Platform
Type Values Removed Values Added
Description A flaw was found in Corosync. A remote unauthenticated attacker can exploit a wrong return value vulnerability in the Corosync membership commit token sanity check by sending a specially crafted User Datagram Protocol (UDP) packet. This can lead to an out-of-bounds read, causing a denial of service (DoS) and potentially disclosing limited memory contents. This vulnerability affects Corosync when running in totemudp/totemudpu mode, which is the default configuration.
Title Corosync: corosync: denial of service and information disclosure via crafted udp packet
First Time appeared Redhat
Redhat enterprise Linux
Redhat openshift
Weaknesses CWE-253
CPEs cpe:/a:redhat:openshift:4
cpe:/o:redhat:enterprise_linux:10
cpe:/o:redhat:enterprise_linux:7
cpe:/o:redhat:enterprise_linux:8
cpe:/o:redhat:enterprise_linux:9
Vendors & Products Redhat
Redhat enterprise Linux
Redhat openshift
References
Metrics cvssV3_1

{'score': 8.2, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H'}

ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}