CVE-2026-35091: A flaw was found in Corosync. A remote unauthenticated attacker can exploit a wrong return value vulnerability in the Corosync membership commit token...

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

Metrics

CVSS 3.1

8.2/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H

EPSS Probability

0.87%

54.1th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-253

Affected Software

Vendor	Product	Versions
Corosync	Corosync	All versions
Redhat	Openshift	4.0
Redhat	Enterprise Linux	7.0
Redhat	Enterprise Linux	8.0
Redhat	Enterprise Linux	9.0
Redhat	Enterprise Linux	10.0

References

Timeline

Published: Apr 1, 2026
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2026-35091?

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

How severe is CVE-2026-35091?

CVE-2026-35091 has a CVSS score of 8.2/10 (HIGH severity). The EPSS model estimates a 0.87% probability of exploitation in the next 30 days.

How do I fix CVE-2026-35091?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.