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Fencer Vulns
high 8.2

CVE-2026-35091 json

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

published 2026-04-01 7 mo ago modified 2026-10-26 13 d ago also EUVD-2026-17879

cvss
8.2
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.9%
EPSS 0.9% chance of exploitation in 30 days, percentile 59%
public exploits
0
none known

Summary

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

Patch / fix

  • Red Hat Red Hat Enterprise Linux 10 0:3.1.9-2.el10_1.1, 0:3.1.10-1.el10_2.1
  • Red Hat Red Hat Enterprise Linux 10.0 Extended Update Support 0:3.1.9-1.el10_0.2
  • Red Hat Red Hat Enterprise Linux 7 Extended Lifecycle Support 0:2.4.5-7.el7_9.3
  • Red Hat Red Hat Enterprise Linux 8 0:3.1.8-1.el8_10.1
  • Red Hat Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support 0:3.1.0-3.el8_4.2
  • Red Hat Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On 0:3.1.0-3.el8_4.2
  • Red Hat Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support 0:3.1.5-2.el8_6.1
  • Red Hat Red Hat Enterprise Linux 8.6 Telecommunications Update Service 0:3.1.5-2.el8_6.1
  • Red Hat Red Hat Enterprise Linux 8.6 Update Services for SAP Solutions 0:3.1.5-2.el8_6.1
  • Red Hat Red Hat Enterprise Linux 8.8 Telecommunications Update Service 0:3.1.7-1.el8_8.1
  • Red Hat Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions 0:3.1.7-1.el8_8.1
  • Red Hat Red Hat Enterprise Linux 9 0:3.1.9-2.el9_7.1, 0:3.1.10-1.el9_8.1
  • Red Hat Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions 0:3.1.5-3.el9_0.1
  • Red Hat Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions 0:3.1.7-1.el9_2.1
  • Red Hat Red Hat Enterprise Linux 9.4 Extended Update Support 0:3.1.8-1.el9_4.1
  • Red Hat Red Hat Enterprise Linux 9.6 Extended Update Support 0:3.1.9-2.el9_6.1
  • corosync Debian 12 3.1.7-1+deb12u2
  • corosync Debian 13 3.1.9-2+deb13u1
  • corosync Debian 14 3.1.10-2

debian advisories DEBIAN-CVE-2026-35091

  • corosync Ubuntu 22.04 LTS 3.1.6-1ubuntu1.2
  • corosync Ubuntu 24.04 LTS 3.1.7-1ubuntu3.2
  • corosync Ubuntu 25.10 3.1.9-2ubuntu1.1

ubuntu advisories UBUNTU-CVE-2026-35091

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • corosync RHEL 7 2.4.5-7.el7_9.3
  • spausedd RHEL 7 2.4.5-7.el7_9.3
  • corosynclib RHEL 7 2.4.5-7.el7_9.3
  • corosync-qnetd RHEL 7 2.4.5-7.el7_9.3
  • corosync-qdevice RHEL 7 2.4.5-7.el7_9.3
  • corosync RHEL 9 3.1.10-1.el9_8.1
  • corosynclib RHEL 9 3.1.10-1.el9_8.1
  • corosync-vqsim RHEL 9 3.1.10-1.el9_8.1

red hat advisories RHSA-2026:20916RHSA-2026:19200RHSA-2026:19043RHSA-2026:14215RHSA-2026:14216RHSA-2026:14213

  • corosync SLE High Availability Extension 15 SP7, SLE High Availability Extension 15 SP6, SLE High Availability Extension 15 SP5 +2 more 2.4.6-150300.12.16.1
  • corosync SLES for SAP applications 16.0 3.1.9-160000.3.1

suse advisories SUSE-SU-2026:1394-1SUSE-SU-2026:21224-1

  • corosync openSUSE Leap 16.0 3.1.9-160000.3.1
  • corosync openSUSE Tumbleweed 3.1.10-4.1

opensuse advisories openSUSE-SU-2026:20505-1openSUSE-SU-2026:10488-1

  • corosync AlmaLinux 10 3.1.10-1.el10_2.1
  • corosynclib AlmaLinux 10 3.1.10-1.el10_2.1
  • corosync-vqsim AlmaLinux 10 3.1.10-1.el10_2.1
  • corosync AlmaLinux 9 3.1.10-1.el9_8.1
  • corosynclib AlmaLinux 9 3.1.10-1.el9_8.1
  • corosync-vqsim AlmaLinux 9 3.1.10-1.el9_8.1
  • corosync AlmaLinux 10 3.1.9-2.el10_1.1
  • corosynclib AlmaLinux 10 3.1.9-2.el10_1.1

almalinux advisories ALSA-2026:19043ALSA-2026:19200ALSA-2026:13644ALSA-2026:13657ALSA-2026:13673

  • corosync Rocky Linux 10 3.1.10-1.el10_2.1
  • corosync Rocky Linux 9 3.1.10-1.el9_8.1
  • corosync Rocky Linux 10 3.1.9-2.el10_1.1
  • corosync Rocky Linux 9 3.1.9-2.el9_7.1
  • corosync Rocky Linux 8 3.1.8-1.el8_10.1

rocky linux advisories RLSA-2026:19043RLSA-2026:19200RLSA-2026:13644RLSA-2026:13673RLSA-2026:13657

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-35091 updated cvss 8.2

corosync: Corosync: Denial of Service and information disclosure via crafted UDP packet

  • Red Hat CodeReady Linux Builder EUS (v.9.4) corosynclib 3.1.8-1.el9_4.1, corosync-vqsim 3.1.8-1.el9_4.1
    fixed: vendor fix RHSA-2026:14212
  • Red Hat CodeReady Linux Builder EUS (v.9.6) corosync-vqsim 3.1.9-2.el9_6.1
    fixed: vendor fix RHSA-2026:14213
  • Red Hat Enterprise Linux AppStream (v. 8) corosync 3.1.8-1.el8_10.1, corosynclib 3.1.8-1.el8_10.1
    fixed: vendor fix RHSA-2026:13657
  • Red Hat Enterprise Linux AppStream (v. 9) corosync 3.1.9-2.el9_7.1, corosync 3.1.10-1.el9_8.1, corosynclib 3.1.9-2.el9_7.1, corosynclib 3.1.10-1.el9_8.1
    fixed: vendor fix RHSA-2026:13673
  • Red Hat Enterprise Linux AppStream (v. 10) corosync 3.1.9-2.el10_1.1, corosync 3.1.10-1.el10_2.1, corosynclib 3.1.9-2.el10_1.1, corosynclib 3.1.10-1.el10_2.1
    fixed: vendor fix RHSA-2026:13644
  • Red Hat Enterprise Linux AppStream AUS (v.8.4) corosync 3.1.0-3.el8_4.2, corosynclib 3.1.0-3.el8_4.2
    fixed: vendor fix RHSA-2026:14215
  • Red Hat Enterprise Linux AppStream AUS (v.8.6) corosync 3.1.5-2.el8_6.1, corosynclib 3.1.5-2.el8_6.1 Red Hat Enterprise Linux AppStream E4S (v.8.6) corosync 3.1.5-2.el8_6.1, corosynclib 3.1.5-2.el8_6.1
    fixed: vendor fix RHSA-2026:14214
  • Red Hat Enterprise Linux AppStream E4S (v.8.8) corosync 3.1.7-1.el8_8.1, corosynclib 3.1.7-1.el8_8.1
    fixed: vendor fix RHSA-2026:14216
show 31 more
  • Red Hat Enterprise Linux AppStream E4S (v.9.0) corosync 3.1.5-3.el9_0.1, corosynclib 3.1.5-3.el9_0.1
    fixed: vendor fix RHSA-2026:14211
  • Red Hat Enterprise Linux AppStream E4S (v.9.2) corosync 3.1.7-1.el9_2.1, corosynclib 3.1.7-1.el9_2.1
    fixed: vendor fix RHSA-2026:14210
  • Red Hat Enterprise Linux AppStream EUS (v. 10.0) corosync 3.1.9-1.el10_0.2, corosynclib 3.1.9-1.el10_0.2
    fixed: vendor fix RHSA-2026:14205
  • Red Hat Enterprise Linux AppStream EUS (v.9.4) corosync 3.1.8-1.el9_4.1, corosynclib 3.1.8-1.el9_4.1
    fixed: vendor fix RHSA-2026:14212
  • Red Hat Enterprise Linux AppStream EUS (v.9.6) corosync 3.1.9-2.el9_6.1, corosynclib 3.1.9-2.el9_6.1
    fixed: vendor fix RHSA-2026:14213
  • Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4) corosync 3.1.0-3.el8_4.2, corosynclib 3.1.0-3.el8_4.2
    fixed: vendor fix RHSA-2026:14215
  • Red Hat Enterprise Linux AppStream TUS (v.8.6) corosync 3.1.5-2.el8_6.1, corosynclib 3.1.5-2.el8_6.1
    fixed: vendor fix RHSA-2026:14214
  • Red Hat Enterprise Linux AppStream TUS (v.8.8) corosync 3.1.7-1.el8_8.1, corosynclib 3.1.7-1.el8_8.1
    fixed: vendor fix RHSA-2026:14216
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) corosync-vqsim 3.1.9-2.el9_7.1, corosync-vqsim 3.1.10-1.el9_8.1
    fixed: vendor fix RHSA-2026:13673
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) corosync-vqsim 3.1.9-2.el10_1.1, corosync-vqsim 3.1.10-1.el10_2.1
    fixed: vendor fix RHSA-2026:13644
  • Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0) corosync-vqsim 3.1.9-1.el10_0.2
    fixed: vendor fix RHSA-2026:14205
  • Red Hat Enterprise Linux CRB (v. 8) corosync-vqsim 3.1.8-1.el8_10.1
    fixed: vendor fix RHSA-2026:13657
  • Red Hat Enterprise Linux High Availability (v. 9) corosync 3.1.9-2.el9_7.1, corosync 3.1.10-1.el9_8.1
    fixed: vendor fix RHSA-2026:13673
  • Red Hat Enterprise Linux High Availability (v. 10) corosync 3.1.9-2.el10_1.1, corosync 3.1.10-1.el10_2.1
    fixed: vendor fix RHSA-2026:13644
  • Red Hat Enterprise Linux High Availability AUS (v.8.4) corosync 3.1.0-3.el8_4.2, spausedd 3.1.0-3.el8_4.2
    fixed: vendor fix RHSA-2026:14215
  • Red Hat Enterprise Linux High Availability E4S (v.8.6) corosync 3.1.5-2.el8_6.1, spausedd 3.1.5-2.el8_6.1
    fixed: vendor fix RHSA-2026:14214
  • Red Hat Enterprise Linux High Availability E4S (v.8.8) corosync 3.1.7-1.el8_8.1, spausedd 3.1.7-1.el8_8.1
    fixed: vendor fix RHSA-2026:14216
  • Red Hat Enterprise Linux High Availability E4S (v.9.0) corosync 3.1.5-3.el9_0.1, corosynclib 3.1.5-3.el9_0.1
    fixed: vendor fix RHSA-2026:14211
  • Red Hat Enterprise Linux High Availability E4S (v.9.2) corosync 3.1.7-1.el9_2.1, corosynclib 3.1.7-1.el9_2.1
    fixed: vendor fix RHSA-2026:14210
  • Red Hat Enterprise Linux High Availability EUS (v. 10.0) corosync 3.1.9-1.el10_0.2
    fixed: vendor fix RHSA-2026:14205
  • Red Hat Enterprise Linux High Availability EUS (v.9.4) corosync 3.1.8-1.el9_4.1, corosynclib 3.1.8-1.el9_4.1
    fixed: vendor fix RHSA-2026:14212
  • Red Hat Enterprise Linux High Availability EUS (v.9.6) corosync 3.1.9-2.el9_6.1
    fixed: vendor fix RHSA-2026:14213
  • Red Hat Enterprise Linux High Availability TUS (v.8.6) corosync 3.1.5-2.el8_6.1, spausedd 3.1.5-2.el8_6.1
    fixed: vendor fix RHSA-2026:14214
  • Red Hat Enterprise Linux High Availability TUS (v.8.8) corosync 3.1.7-1.el8_8.1, spausedd 3.1.7-1.el8_8.1
    fixed: vendor fix RHSA-2026:14216
  • Red Hat Enterprise Linux HighAvailability (v. 8) corosync 3.1.8-1.el8_10.1, spausedd 3.1.8-1.el8_10.1
    fixed: vendor fix RHSA-2026:13657
  • Red Hat Enterprise Linux HighAvailability EUS EXTENSION (v.8.4) corosync 3.1.0-3.el8_4.2, spausedd 3.1.0-3.el8_4.2
    fixed: vendor fix RHSA-2026:14215
  • Red Hat Enterprise Linux Resilient Storage (v. 9) corosync 3.1.9-2.el9_7.1, corosync 3.1.10-1.el9_8.1
    fixed: vendor fix RHSA-2026:13673
  • Red Hat Enterprise Linux Resilient Storage E4S (v.9.2) corosync 3.1.7-1.el9_2.1, corosynclib 3.1.7-1.el9_2.1
    fixed: vendor fix RHSA-2026:14210
  • Red Hat Enterprise Linux Resilient Storage EUS (v.9.4) corosync 3.1.8-1.el9_4.1, corosynclib 3.1.8-1.el9_4.1
    fixed: vendor fix RHSA-2026:14212
  • Red Hat Enterprise Linux Resilient Storage EUS (v.9.6) corosync 3.1.9-2.el9_6.1
    fixed: vendor fix RHSA-2026:14213
  • Red Hat Enterprise Linux ResilientStorage (v. 8) corosync 3.1.8-1.el8_10.1, spausedd 3.1.8-1.el8_10.1
    fixed: vendor fix RHSA-2026:13657

3 more fixed, 1 more not affected in the full advisory

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
7 mo ago

Exploit prediction

0.88% chance of exploitation in the next 30 days, higher than 59% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • bugzilla.redhat.com https://bugzilla.redhat.com/show_bug.cgi?id=2453169 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 8.2 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H

Affected products

  • Red Hat Red Hat Enterprise Linux 10
  • Red Hat Red Hat Enterprise Linux 10.0 Extended Update Support
  • Red Hat Red Hat Enterprise Linux 7 Extended Lifecycle Support
  • Red Hat Red Hat Enterprise Linux 8
  • Red Hat Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support
  • Red Hat Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On
  • Red Hat Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support
  • Red Hat Red Hat Enterprise Linux 8.6 Telecommunications Update Service
  • Red Hat Red Hat Enterprise Linux 8.6 Update Services for SAP Solutions
  • Red Hat Red Hat Enterprise Linux 8.8 Telecommunications Update Service
  • Red Hat Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions
  • Red Hat Red Hat Enterprise Linux 9
  • Red Hat Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions
  • Red Hat Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions
  • Red Hat Red Hat Enterprise Linux 9.4 Extended Update Support
  • Red Hat Red Hat Enterprise Linux 9.6 Extended Update Support
  • Red Hat Red Hat OpenShift Container Platform 4

Classification

Weakness
  • CWE-253 Incorrect Check of Function Return Value

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.