CVE-2026-35091

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

HIGH
8.2
CVSS Score
Published: April 1, 2026 at 01:18 PM UTC
Updated: October 26, 2026 at 09:10 PM UTC
3 products affected across 2 vendorsEnterprise LinuxOpenshiftCorosync

Using Red Hat Enterprise Linux 10 by Red Hat?

Get instant alerts when new vulnerabilities affect Red Hat Enterprise Linux 10 - before attackers find them.

Real-time alertsTrack your software stackFree plan available
Severity
HIGH8.2
Exploit prediction
EPSS 0.9%
SSVC
No known exploit

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

All versions
Vendor states this is fixed in 0:2.4.5-7.el7_9.3 (unaffected)
Vendor states this is fixed in 0:3.1.0-3.el8_4.2 (unaffected)
Vendor states this is fixed in 0:3.1.10-1.el10_2.1 (unaffected)
Vendor states this is fixed in 0:3.1.10-1.el9_8.1 (unaffected)
Vendor states this is fixed in 0:3.1.5-2.el8_6.1 (unaffected)
Vendor states this is fixed in 0:3.1.5-3.el9_0.1 (unaffected)
Vendor states this is fixed in 0:3.1.7-1.el8_8.1 (unaffected)
Vendor states this is fixed in 0:3.1.7-1.el9_2.1 (unaffected)
Vendor states this is fixed in 0:3.1.8-1.el8_10.1 (unaffected)
Vendor states this is fixed in 0:3.1.8-1.el9_4.1 (unaffected)
Vendor states this is fixed in 0:3.1.9-1.el10_0.2 (unaffected)
Vendor states this is fixed in 0:3.1.9-2.el10_1.1 (unaffected)
Vendor states this is fixed in 0:3.1.9-2.el9_6.1 (unaffected)
Vendor states this is fixed in 0:3.1.9-2.el9_7.1 (unaffected)

References (17)

VDB Entryx_refsource_REDHATThird Party Advisory
Source: cverecord
https://access.redhat.com/security/cve/CVE-2026-35091
ExploitThird Party Advisory
Source: cverecord
https://bugzilla.redhat.com/show_bug.cgi?id=2453169
Issue Trackingx_refsource_REDHAT
Source: cverecord
https://bugzilla.redhat.com/show_bug.cgi?id=2453813
Vendor Advisoryx_refsource_REDHAT
Source: cverecord
https://access.redhat.com/errata/RHSA-2026:13644
Vendor Advisoryx_refsource_REDHAT
Source: cverecord
https://access.redhat.com/errata/RHSA-2026:13657
Vendor Advisoryx_refsource_REDHAT
Source: cverecord
https://access.redhat.com/errata/RHSA-2026:13673
Vendor Advisoryx_refsource_REDHAT
Source: cverecord
https://access.redhat.com/errata/RHSA-2026:14205
Vendor Advisoryx_refsource_REDHAT
Source: cverecord
https://access.redhat.com/errata/RHSA-2026:14214

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

8.2HIGHredhat
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
LOW
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-253

Get alerted

Stop reading CVE feeds looking for your own stack

Track the products you run and VulnTracker tells you when a new CVE affects them — with what is known about fixing it, and nothing about the rest.

Free plan, no card