CVE-2026-35091
published 2026-04-01CVE-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…
PriorityP349high8.2CVSS 3.1
AVNACLPRNUINSUCLINAH
EPSS
0.87%
54.6th percentile
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
Affected
6 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| debian | corosync | — | — |
| redhat | enterprise_linux | — | — |
| redhat | enterprise_linux | — | — |
| redhat | enterprise_linux | — | — |
| redhat | enterprise_linux | — | — |
| redhat | openshift | — | — |
CVSS provenance
nvdv3.18.2HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H
osv8.2HIGH
vendor_debian8.2HIGH
vendor_redhat8.2HIGH
vendor_ubuntu8.2HIGH
Stop checking back — get the weekly exploitation signal.
Every Monday: what got weaponized or added to CISA KEV in the last seven days — each CVE cross-linked to its PoC, Nuclei template, and detection rule. Free, one email a week, unsubscribe in one click.
VulDB
Corosync UDP Packet function return value (Nessus ID 306047)
vuldb·2026-04-13·CVSS 8.2
CVE-2026-35091 [HIGH] Corosync UDP Packet function return value (Nessus ID 306047)
A vulnerability marked as critical has been reported in Corosync. This affects an unknown function of the component UDP Packet Handler. The manipulation leads to incorrect check of function return value.
This vulnerability is traded as CVE-2026-35091. It is possible to initiate the attack remotely. There is no exploit available.
To fix this issue, it is recommended to deploy a patch.
OSV
CVE-2026-35091: (A flaw was found in Corosync
osv·2026-04-02·CVSS 8.2
CVE-2026-35091 [HIGH] CVE-2026-35091: (A flaw was found in Corosync
(A flaw was found in Corosync. A remote unauthenticated attacker can ex ...)
OSV
CVE-2026-35091: A flaw was found in Corosync
osv·2026-04-01·CVSS 8.2
CVE-2026-35091 [HIGH] CVE-2026-35091: A flaw was found in Corosync
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.
GHSA
GHSA-hmg2-5h4j-37m9: A flaw was found in Corosync
ghsa_unreviewed·2026-04-01
CVE-2026-35091 [HIGH] CWE-253 GHSA-hmg2-5h4j-37m9: A flaw was found in Corosync
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.
Ubuntu
Corosync vulnerabilities
vendor_ubuntu·2026-04-13·CVSS 8.2
CVE-2026-35092 [HIGH] Corosync vulnerabilities
Title: Corosync vulnerabilities
Summary: Several security issues were fixed in Corosync.
It was discovered that Corosync incorrectly handled the membership commit
token validity check. A remote attacker could use this issue to cause
Corosync to crash, resulting in a denial of service, or to possibly obtain
a small quantity of sensitive information. (CVE-2026-35091)
It was discovered that Corosync incorrectly handled join message
validation. A remote attacker could possibly use this issue to cause
Corosync to crash, resulting in a denial of service. (CVE-2026-35092)
Instructions: After a standard system update you need to restart Corosync to make all the
necessary changes.
Red Hat
corosync: Corosync: Denial of Service and information disclosure via crafted UDP packet
vendor_redhat·2026-04-01·CVSS 8.2
CVE-2026-35091 [HIGH] CWE-253 corosync: Corosync: Denial of Service and information disclosure via crafted UDP packet
corosync: Corosync: Denial of Service and information disclosure via crafted UDP packet
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 ca
Debian
CVE-2026-35091: corosync - A flaw was found in Corosync. A remote unauthenticated attacker can exploit a wr...
vendor_debian·2026·CVSS 8.2
CVE-2026-35091 [HIGH] CVE-2026-35091: corosync - A flaw was found in Corosync. A remote unauthenticated attacker can exploit a wr...
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.
Scope: local
bookworm: open
bullseye: open
forky: open
sid: open
trixie: open
No detection rules found.
No public exploits indexed.
Wiz
CVE-2026-35091 Impact, Exploitability, and Mitigation Steps | Wiz
blogs_wiz·CVSS 8.2
CVE-2026-35091 [HIGH] CVE-2026-35091 Impact, Exploitability, and Mitigation Steps | Wiz
## CVE-2026-35091 :
Linux Debian vulnerability analysis and mitigation
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.
Source : NVD
## 8.2
Score
Published April 1, 2026
Severity HIGH
CNA Score 8.2
Affected Technologies
Linux Debian
Linux Red Hat
Has Public Exploit Yes
Has CISA KEV Exploit No
CISA KEV Release Date N/A
CISA KEV Due Date N/A
Exploitation Proba
Bugzilla
CVE-2026-35091 corosync: Corosync: Denial of Service and information disclosure via crafted UDP packet [fedora-all]
bugzilla·2026-04-01·CVSS 8.2
CVE-2026-35091 [HIGH] CVE-2026-35091 corosync: Corosync: Denial of Service and information disclosure via crafted UDP packet [fedora-all]
CVE-2026-35091 corosync: Corosync: Denial of Service and information disclosure via crafted UDP packet [fedora-all]
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.
Discussion:
FEDORA-2026-e34a334e81 (corosync-3.1.10-5.fc44) has been submitted as an update to Fedora 44.
https://bodhi.fedoraproject.org/updates/FEDORA-2026-e34a334e81
---
FEDORA-2026-ee4ff58256 (corosync-3.1.10-2.fc43) has been submitted as an update to Fedora 43.
https://bodhi.fedoraproject.org/updates/FEDORA-2026-ee4ff58256
---
FEDORA-2026-95ee0edcd5 (corosync-3.1.9-4.fc42) has been submitted as an update to Fedora 42.
https://bodhi.fedoraprojec
Bugzilla
CVE-2026-35091 corosync: Corosync: Denial of Service and information disclosure via crafted UDP packet
bugzilla·2026-04-01·CVSS 8.2
CVE-2026-35091 [HIGH] CVE-2026-35091 corosync: Corosync: Denial of Service and information disclosure via crafted UDP packet
CVE-2026-35091 corosync: Corosync: Denial of Service and information disclosure via crafted UDP packet
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
https://access.redhat.com/errata/RHSA-2026:13644https://access.redhat.com/errata/RHSA-2026:13657https://access.redhat.com/errata/RHSA-2026:13673https://access.redhat.com/errata/RHSA-2026:14205https://access.redhat.com/errata/RHSA-2026:14210https://access.redhat.com/errata/RHSA-2026:14211https://access.redhat.com/errata/RHSA-2026:14212https://access.redhat.com/errata/RHSA-2026:14213https://access.redhat.com/errata/RHSA-2026:14214https://access.redhat.com/errata/RHSA-2026:14215https://access.redhat.com/errata/RHSA-2026:14216https://access.redhat.com/errata/RHSA-2026:19043https://access.redhat.com/errata/RHSA-2026:19200https://access.redhat.com/errata/RHSA-2026:20916https://access.redhat.com/security/cve/CVE-2026-35091https://bugzilla.redhat.com/show_bug.cgi?id=2453169https://bugzilla.redhat.com/show_bug.cgi?id=2453813
2026-04-01
Published