Bug 2453813 (CVE-2026-35091)

Summary:	CVE-2026-35091 corosync: Corosync: Denial of Service and information disclosure via crafted UDP packet
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	CC:	rhel-process-autobot, security-response-team, watson-tool-maintainers
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	---
Doc Text:	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	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:	2453815
Bug Blocks:

Description OSIDB Bzimport 2026-04-01 11:31:24 UTC

Wrong return value vulnerability in the Corosync membership commit token sanity check in exec/totemsrp.c. The flaw occurs in check_memb_commit_token_sanity() where truncated messages (msg_len < sizeof(struct memb_commit_token)) incorrectly return 0 (success) instead of -1 (failure). As a result, message_handler_memb_commit_token() continues processing attacker-controlled, undersized input, performs an allocation based on the short length, and then accesses struct memb_commit_token fields beyond the allocated region, triggering an out-of-bounds read (ASAN-confirmed). This can be exploited remotely without authentication in totemudp/totemudpu mode by sending a single crafted UDP packet to the Corosync port (default 5405), causing a denial of service and potentially leaking limited memory contents.

Comment 2 errata-xmlrpc 2026-05-05 09:18:44 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 10

Via RHSA-2026:13644 https://access.redhat.com/errata/RHSA-2026:13644

Comment 3 errata-xmlrpc 2026-05-05 10:04:50 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2026:13657 https://access.redhat.com/errata/RHSA-2026:13657

Comment 4 errata-xmlrpc 2026-05-05 10:23:46 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9

Via RHSA-2026:13673 https://access.redhat.com/errata/RHSA-2026:13673

Comment 5 errata-xmlrpc 2026-05-06 15:47:18 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 10.0 Extended Update Support

Via RHSA-2026:14205 https://access.redhat.com/errata/RHSA-2026:14205

Comment 6 errata-xmlrpc 2026-05-06 16:10:44 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions

Via RHSA-2026:14211 https://access.redhat.com/errata/RHSA-2026:14211

Comment 7 errata-xmlrpc 2026-05-06 16:15:04 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support
  Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On

Via RHSA-2026:14215 https://access.redhat.com/errata/RHSA-2026:14215

Comment 8 errata-xmlrpc 2026-05-06 16:15:27 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions

Via RHSA-2026:14210 https://access.redhat.com/errata/RHSA-2026:14210

Comment 9 errata-xmlrpc 2026-05-06 16:20:05 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support
  Red Hat Enterprise Linux 8.6 Update Services for SAP Solutions
  Red Hat Enterprise Linux 8.6 Telecommunications Update Service

Via RHSA-2026:14214 https://access.redhat.com/errata/RHSA-2026:14214

Comment 10 errata-xmlrpc 2026-05-06 16:25:54 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions
  Red Hat Enterprise Linux 8.8 Telecommunications Update Service

Via RHSA-2026:14216 https://access.redhat.com/errata/RHSA-2026:14216

Comment 11 errata-xmlrpc 2026-05-06 16:27:51 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9.4 Extended Update Support

Via RHSA-2026:14212 https://access.redhat.com/errata/RHSA-2026:14212

Comment 12 errata-xmlrpc 2026-05-06 16:30:22 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9.6 Extended Update Support

Via RHSA-2026:14213 https://access.redhat.com/errata/RHSA-2026:14213

Comment 13 errata-xmlrpc 2026-05-19 13:06:26 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 10

Via RHSA-2026:19043 https://access.redhat.com/errata/RHSA-2026:19043

Comment 14 errata-xmlrpc 2026-05-19 18:00:55 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9

Via RHSA-2026:19200 https://access.redhat.com/errata/RHSA-2026:19200

Comment 15 errata-xmlrpc 2026-05-26 14:26:18 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7 Extended Lifecycle Support

Via RHSA-2026:20916 https://access.redhat.com/errata/RHSA-2026:20916